417 results on '"Morello, Andrea"'
Search Results
202. ChemInform Abstract: Quantum Nanomagnets and Nuclear Spins: An Overview
- Author
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Morello, Andrea, primary
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- 2008
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203. Dynamics and thermalization of the nuclear spin bath in the single-molecule magnetMn12−ac: Test for the theory of spin tunneling
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Morello, Andrea, primary and de Jongh, L. J., additional
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- 2007
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204. Pairwise Decoherence in Coupled Spin Qubit Networks
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Morello, Andrea, primary, Stamp, P. C. E., additional, and Tupitsyn, Igor S., additional
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- 2006
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- View/download PDF
205. Pneumatic Vehicular Suspension With a Controllable Stiffness Spring
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Ferraresi, Carlo, primary, Franco, Walter, additional, Quaglia, Giuseppe, additional, Morello, Andrea, additional, and Pierucci, Domenico, additional
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- 2006
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206. Bell's inequality violation with spins in silicon
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Dehollain, Juan P., Simmons, Stephanie, Muhonen, Juha T., Kalra, Rachpon, Laucht, Arne, Hudson, Fay, Itoh, Kohei M., Jamieson, David N., McCallum, Jeffrey C., Dzurak, Andrew S., and Morello, Andrea
- Abstract
Bell's theorem proves the existence of entangled quantum states with no classical counterpart. An experimental violation of Bell's inequality demands simultaneously high fidelities in the preparation, manipulation and measurement of multipartite quantum entangled states, and provides a single-number benchmark for the performance of devices that use such states for quantum computing. We demonstrate a Bell/ Clauser–Horne–Shimony–Holt inequality violation with Bell signals up to 2.70(9), using the electron and the nuclear spins of a single phosphorus atom embedded in a silicon nanoelectronic device. Two-qubit state tomography reveals that our prepared states match the target maximally entangled Bell states with >96% fidelity. These experiments demonstrate complete control of the two-qubit Hilbert space of a phosphorus atom and highlight the important function of the nuclear qubit to expand the computational basis and maximize the readout fidelity.
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- 2016
- Full Text
- View/download PDF
207. Circuit-quantum electrodynamics with direct magnetic coupling to single-atom spin qubits in isotopically enriched 28Si.
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Tosi, Guilherme, Mohiyaddin, Fahd A., Huebl, Hans, and Morello, Andrea
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QUANTUM electrodynamics ,NANOFABRICATION ,MAGNETIC coupling ,RESONATORS ,MAGNETIC fields - Abstract
Recent advances in silicon nanofabrication have allowed the manipulation of spin qubits that are extremely isolated from noise sources, being therefore the semiconductor equivalent of single atoms in vacuum. We investigate the possibility of directly coupling an electron spin qubit to a superconducting resonator magnetic vacuum field. By using resonators modified to increase the vacuum magnetic field at the qubit location, and isotopically purified
28 Si substrates, it is possible to achieve coupling rates faster than the single spin dephasing. This opens up new avenues for circuitquantum electrodynamics with spins, and provides a pathway for dispersive read-out of spin qubits via superconducting resonators. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
208. High-fidelity adiabatic inversion of a 31P electron spin qubit in natural silicon.
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Laucht, Arne, Kalra, Rachpon, Muhonen, Juha T., Dehollain, Juan P., Mohiyaddin, Fahd A., Hudson, Fay, McCallum, Jeffrey C., Jamieson, David N., Dzurak, Andrew S., and Morello, Andrea
- Subjects
ADIABATIC processes ,ELECTRON spin ,QUBITS ,SILICON ,SEMICONDUCTORS ,NUCLEAR spin - Abstract
The main limitation to the high-fidelity quantum control of spins in semiconductors is the presence of strongly fluctuating fields arising from the nuclear spin bath of the host material. We demonstrate here a substantial improvement in single-qubit inversion fidelities for an electron spin qubit bound to a 31P atom in natural silicon, by applying adiabatic sweeps instead of narrow-band pulses. We achieve an inversion fidelity of 97%, and we observe signatures in the spin resonance spectra and the spin coherence time that are consistent with the presence of an additional exchange-coupled donor. This work highlights the effectiveness of simple adiabatic inversion techniques for spin control in fluctuating environments. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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- View/download PDF
209. Donor qubits in silicon: Electrical control of nuclear spins
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Morello, Andrea
- Published
- 2017
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210. Quantum spintronics: Single spins in silicon carbide.
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Morello, Andrea
- Subjects
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SILICON carbide , *SPINTRONICS , *ELECTRON spin polarization - Abstract
An introduction is presented in which the authors discusses articles within the issue on topics including the spins in silicon carbide lattice, coherent control of the electronic spin, and single-spin detection and coherent manipulation at room temperature.
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- 2015
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211. Quantum information: Atoms and circuits unite in silicon.
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Morello, Andrea
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QUANTUM theory , *ADULT education workshops , *SILICON , *NUCLEAR spin , *ERBIUM - Abstract
The article discusses the highlights of the 9th International Workshop on Silicon Quantum Electronics held in Villard-de-Lans in France in February 2013. The workshop explored the integration of a variety of quantum systems that can be hosted in silicon. One of the presentations identified donor nuclear spins in silicon which surpass atomic systems in vacuum as the most coherent quantum system in the solid state. Another presentation dealt with optical excitation of a single erbium atom.
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- 2013
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212. ChemInform Abstract: Quantum Nanomagnets and Nuclear Spins: An Overview.
- Author
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Morello, Andrea
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- 2009
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- View/download PDF
213. A single-atom quantum memory in silicon
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Morello, Andrea [Univ. of New South Wales, Sydney, NSW (Australia)] (ORCID:000000017445699X)
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- 2017
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214. Optimization of a solid-state electron spin qubit using Gate Set Tomography
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Morello, Andrea [Univ. of New South Wales, Sydney, NSW (Australia)]
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- 2016
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215. Transport of spin qubits with donor chains under realistic experimental conditions
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Morello, Andrea [UNSW Australia, Sydney, NSW (Australia)]
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- 2016
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216. Colchicine inhibits the prothrombotic effects of oxLDL in human endothelial cells.
- Author
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Cimmino, Giovanni, Conte, Stefano, Morello, Andrea, Pellegrino, Grazia, Marra, Laura, Calì, Gaetano, Golino, Paolo, and Cirillo, Plinio
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ENDOTHELIAL cells , *COLCHICINE , *VASCULAR endothelial cells , *LOW density lipoprotein receptors , *WESTERN immunoblotting - Abstract
Tissue Factor (TF) plays a pivotal role in coronary thrombosis. Oxidized low-density lipoproteins (oxLDL) are crucial in development of atherosclerosclerosis. Moreover, oxLDL are known to induce TF expression on several cell types including endothelial cells. The lectin-type oxidized LDL receptor 1 (LOX-1) represent the oxLDL receptor. Colchicine is an anti-mitotic drug recently proven to have beneficial effects in cardiovascular disease via unknown mechanisms. Thus, we aim at investigating colchicine effects on TF expression in oxLDL stimulated human vascular endothelial cells (HUVEC). Some molecular mechanism(s) potentially involved were investigated. HUVEC were pre-incubated with colchicine 10 μM for 1 h and then stimulated with oxLDL (50 μg/mL). TF gene (RT-PCR), protein (western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. TF translocation to cell surface was investigated by immunofluorescence. NF-κB/IκB axis was examined by western blot analysis and translocation assay. Finally, LOX-1 expression was also investigated. Colchicine significantly reduced TF gene and protein expression as well as its procoagulant activity in oxLDL-treated HUVEC. These effects seem to be related mainly to action of colchicine on microtubules that, in turn, modulate TF trafficking in the cytoplasm, NF-κB/IκB pathway and LOX-1 expression. Data of the present study, although in vitro, indicate that one of the hypothetical mechanisms by which colchicine exert protective cardiovascular effects might be its ability to inhibit the pro-thrombotic activity of oxLDL. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
217. Uric Acid Induces a Proatherothrombotic Phenotype in Human Endothelial Cells by Imbalancing the Tissue Factor/Tissue Factor Pathway Inhibitor Pathway
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Giovanni Cimmino, Stefano Conte, Laura Marra, Andrea Morello, Mariarosaria Morello, Gennaro De Rosa, Martino Pepe, Akhmetzhan Sugraliyev, Paolo Golino, Plinio Cirillo, Cimmino, Giovanni, Conte, Stefano, Marra, Laura, Morello, Andrea, Morello, Mariarosaria, De Rosa, Gennaro, Pepe, Martino, Sugraliyev, Akhmetzhan, Golino, Paolo, and Cirillo, Plinio
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Hematology - Abstract
Background Several evidence show that elevated plasma levels of uric acid (UA) are associated with the increased risk of developing atherothrombotic cardiovascular events. Hyperuricemia is a risk factor for endothelial dysfunction (ED). ED is involved in the pathophysiology of atherothrombosis since dysfunctional cells lose their physiological, antithrombotic properties. We have investigated whether UA might promote ED by modulating the tissue factor (TF)/TF pathway inhibitor (TFPI) balance by finally changing the antithrombotic characteristics of endothelial cells. Methods Human umbilical vein endothelial cells were incubated with increasing doses of UA (up to 9 mg/dL). TF gene and protein expressions were evaluated by real-time polymerase chain reaction (PCR) and Western blot. Surface expression and procoagulant activity were assessed by FACS (fluorescence activated cell sorting) analysis and coagulation assay. The mRNA and protein levels of TFPI were measured by real-time PCR and Western blot. The roles of inflammasome and nuclear factor-κB (NF-κB) as possible mechanism(s) of action of the UA on TF/TFPI balance were also investigated. Results UA significantly increased TF gene and protein levels, surface expression, and procoagulant activity. In parallel, TFPI levels were significantly reduced. The NF-κB pathways appeared to be involved in modulating these phenomena. Additionally, inflammasome might also play a role. Conclusion The present in vitro study shows that one of the mechanisms by which high levels of UA contribute to ED might be the imbalance between TF/TFPI levels in endothelial cells, shifting them to a nonphysiological, prothrombotic phenotype. These UA effects might hypothetically explain, at least in part, the relationship observed between elevated plasma levels of UA and cardiovascular events.
- Published
- 2022
218. Colchicine reduces platelet aggregation by modulating cytoskeleton rearrangement via inhibition of cofilin and LIM domain kinase 1.
- Author
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Cimmino, Giovanni, Tarallo, Roberta, Conte, Stefano, Morello, Andrea, Pellegrino, Grazia, Loffredo, Francesco S., Calì, Gaetano, De Luca, Nicola, Golino, Paolo, Trimarco, Bruno, and Cirillo, Plinio
- Subjects
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COLCHICINE , *PLATELET aggregation inhibitors , *CYTOSKELETON , *PATHOLOGICAL physiology , *ACUTE coronary syndrome , *TUBULINS , *IMMUNOHISTOCHEMISTRY - Abstract
Abstract Introduction Platelets activation/aggregation with subsequent thrombus formation is the main event in the pathophysiology of acute coronary syndrome. Once activated, platelets show an extensive cytoskeleton rearrangement that leads to recruitment of additional platelets to finally cause haemostatic plug formation. Thus, the cytoskeleton plays a pivotal role in this phenomenon. Colchicine (COLC) is an anti-inflammatory drug proven to reduce major cardiovascular events in patients with coronary artery disease. The molecular mechanisms by which COLC exerts these protective effects remain partially still unknown. Since COLC causes disruption of tubulin, a component of cell cytoskeleton, we investigated whether this drug might interfere with platelet aggregation by acting on cytoskeleton rearrangement. Methods and results Platelets isolated from healthy volunteers were activated with Adenosine Diphosphate (ADP, 20 μM) Collagen (COLL, 60 μg/ml) and Thrombin Activating Receptor Peptide (TRAP 25 μM) with/without COLC 10 μM pretreatment. After stimulus, aggregation was measured by light aggregometry overtime. Microtubules structure was assessed by immunohistochemistry and key proteins involved in regulation of actin-filament assembly and contractility such as Myosin Phosphatase Targeting subunit (MYPT), LIM domain kinase 1(LIMK1) and cofilin were evaluated by Western Blot analysis. Colchicine pretreatment significantly blunted ADP/COLL/TRAP-induced platelet aggregation (up to 40%). COLC effects appeared mediated by microtubules depolymerization and cytoskeleton disarrangement associated to inactivation of MYPT and LIMK1 that finally interfered with cofilin activity. Conclusions Our data indicate that colchicine exerts anti-platelet effects in vitro via inhibition of key proteins involved in cytoskeleton rearrangement, suggesting that its beneficial cardiovascular properties may be due, at least in part, to an inhibitory effect of platelet activity. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
219. Vibration-induced electrical noise in a cryogen-free dilution refrigerator: Characterization, mitigation, and impact on qubit coherence
- Author
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Morello, Andrea [Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052 (Australia)]
- Published
- 2016
- Full Text
- View/download PDF
220. Colchicine inhibits the prothrombotic effects of oxLDL in human endothelial cells
- Author
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Andrea Morello, Gaetano Calì, Grazia Pellegrino, Paolo Golino, Laura Marra, Giovanni Cimmino, Plinio Cirillo, Stefano Conte, Cimmino, Giovanni, Conte, Stefano, Morello, Andrea, Pellegrino, Grazia, Marra, Laura, Calì, Gaetano, Golino, Paolo, and Cirillo, Plinio
- Subjects
0301 basic medicine ,Cell type ,Physiology ,Cell ,030204 cardiovascular system & hematology ,Thromboplastin ,03 medical and health sciences ,chemistry.chemical_compound ,Tissue factor ,0302 clinical medicine ,Western blot ,Fibrinolytic Agents ,medicine ,Human Umbilical Vein Endothelial Cells ,Colchicine ,Humans ,Receptor ,Blood Coagulation ,Cells, Cultured ,Pharmacology ,medicine.diagnostic_test ,NF-kappa B ,Scavenger Receptors, Class E ,In vitro ,Cell biology ,Lipoproteins, LDL ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Cytoplasm ,Factor Xa ,Thrombosi ,Molecular Medicine ,lipids (amino acids, peptides, and proteins) ,I-kappa B Proteins - Abstract
Background Tissue Factor (TF) plays a pivotal role in coronary thrombosis. Oxidized low-density lipoproteins (oxLDL) are crucial in development of atherosclerosclerosis. Moreover, oxLDL are known to induce TF expression on several cell types including endothelial cells. The lectin-type oxidized LDL receptor 1 (LOX-1) represent the oxLDL receptor. Colchicine is an anti-mitotic drug recently proven to have beneficial effects in cardiovascular disease via unknown mechanisms. Thus, we aim at investigating colchicine effects on TF expression in oxLDL stimulated human vascular endothelial cells (HUVEC). Some molecular mechanism(s) potentially involved were investigated. Methods HUVEC were pre-incubated with colchicine 10 μM for 1 h and then stimulated with oxLDL (50 μg/mL). TF gene (RT-PCR), protein (western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. TF translocation to cell surface was investigated by immunofluorescence. NF-κB/IκB axis was examined by western blot analysis and translocation assay. Finally, LOX-1 expression was also investigated. Results Colchicine significantly reduced TF gene and protein expression as well as its procoagulant activity in oxLDL-treated HUVEC. These effects seem to be related mainly to action of colchicine on microtubules that, in turn, modulate TF trafficking in the cytoplasm, NF-κB/IκB pathway and LOX-1 expression. Conclusions Data of the present study, although in vitro, indicate that one of the hypothetical mechanisms by which colchicine exert protective cardiovascular effects might be its ability to inhibit the pro-thrombotic activity of oxLDL.
- Published
- 2021
221. Single-Shot Readout and Relaxation of Singlet and Triplet States in Exchange-Coupled 31P Electron Spins in Silicon.
- Author
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Dehollain, Juan P., Muhonen, Juha T., Tan, Kuan Y., Saraiva, Andre, Jamieson, David N., Dzurak, Andrew S., and Morello, Andrea
- Subjects
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ELECTRIC properties of silicon , *SINGLET state (Quantum mechanics) , *TRIPLET state (Quantum mechanics) , *ELECTRON spin , *QUANTUM logic , *QUBITS - Abstract
We present the experimental observation of a large exchange coupling J≈300 μeV between two P31 electron spin qubits in silicon. The singlet and triplet states of the coupled spins are monitored in real time by a single-electron transistor, which detects ionization from tunnel-rate-dependent processes in the coupled spin system, yielding single-shot readout fidelities above 95%. The triplet to singlet relaxation time T1≈4 ms at zero magnetic field agrees with the theoretical prediction for J-coupled P31 dimers in silicon. The time evolution of the two-electron state populations gives further insight into the valley-orbit eigenstates of the donor dimer, valley selection rules and relaxation rates, and the role of hyperfine interactions. These results pave the way to the realization of two-qubit quantum logic gates with spins in silicon and highlight the necessity to adopt gating schemes compatible with weak J-coupling strengths. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
222. Oxidized low-density lipoproteins induce tissue factor expression in T-lymphocytes via activation of lectin-like oxidized low-density lipoprotein receptor-1
- Author
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Paolo Golino, Tatsuya Sawamura, Giusi Barra, Giovanni Cimmino, Giuseppe Ambrosio, Francesco Loffredo, Grazia Pellegrino, Plinio Cirillo, Andrea Morello, Giulia Arena, Stefano Conte, Raffaele De Palma, Gaetano Calì, Lucio Maresca, Cimmino, G., Cirillo, P., Conte, S., Pellegrino, G., Barra, G., Maresca, L., Morello, A., Cali, G., Loffredo, F., De Palma, R., Arena, G., Sawamura, T., Ambrosio, G., Golino, P., Cimmino, Giovanni, Cirillo, Plinio, Conte, Stefano, Pellegrino, Grazia, Barra, Giusi, Maresca, Lucio, Morello, Andrea, Calì, Gaetano, Loffredo, Francesco, De Palma, Raffaele, Arena, Giulia, Sawamura, Tatsuya, Ambrosio, Giuseppe, and Golino, Paolo
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Carotid Artery Diseases ,0301 basic medicine ,T-lymphocyte ,Physiology ,Lipoproteins ,T-Lymphocytes ,CD3 ,Inflammation ,030204 cardiovascular system & hematology ,Thromboplastin ,Superoxide dismutase ,03 medical and health sciences ,Tissue factor ,0302 clinical medicine ,Physiology (medical) ,medicine ,Humans ,Lipoprotein ,Cells, Cultured ,biology ,Chemistry ,NF-kappa B ,NADPH Oxidases ,Atherosclerosis ,Tissue Factor ,Scavenger Receptors, Class E ,Free radical scavenger ,Molecular biology ,Plaque, Atherosclerotic ,In vitro ,Up-Regulation ,Lipoproteins, LDL ,030104 developmental biology ,Atherosclerosi ,biology.protein ,lipids (amino acids, peptides, and proteins) ,medicine.symptom ,Reactive Oxygen Species ,Cardiology and Cardiovascular Medicine ,CD8 - Abstract
Aims T-lymphocytes plays an important role in the pathophysiology of acute coronary syndromes. T-cell activation in vitro by pro-inflammatory cytokines may lead to functional tissue factor (TF) expression, indicating a possible contribution of immunity to thrombosis. Oxidized low-density lipoproteins (oxLDLs) are found abundantly in atherosclerotic plaques. We aimed at evaluating the effects of oxLDLs on TF expression in T cells and the role of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1). Methods and results CD3+ cells were isolated from healthy volunteers. Gene, protein, and surface expression of TF, as well as of LOX-1, were assessed at different time-points after oxLDL stimulation. To determine whether oxLDL-induced TF was LOX-1 dependent, T cells were pre-incubated with an LOX-1 inhibiting peptide (L-RBP) or with an anti-LOX-1 blocking antibody. To exclude that TF expression was mediated by reactive oxygen species (ROS) generation, oxLDL-stimulated T cells were pre-incubated with superoxide dismutase + catalase or with 4-Hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol), an intracellular free radical scavenger. Finally, to determine if the observed findings in vitro may have a biological relevance, the presence of CD3+/TF+/LOX-1+ cells was evaluated by immunofluorescence in human carotid atherosclerotic lesions. oxLDLs induced functionally active TF expression in T cells in a dose- and time-dependent manner, independently on ROS generation. No effect was observed in native LDL-treated T cells. LOX-1 expression was also induced by oxLDLs in a time- and dose-dependent manner. Pre-incubation with L-RBP or anti-LOX-1 antibody almost completely inhibited oxLDL-mediated TF expression. Interestingly, human carotid plaques showed significant infiltration of CD3+ cells (mainly CD8+ cells), some of which were positive for both TF and LOX-1. Conclusion oxLDLs induce functional TF expression in T-lymphocytes in vitro via interaction of oxLDLs with LOX-1. Human carotid atherosclerotic plaques contain CD3+/CD8+cells that express both TF and LOX-1, indicating that also in patients these mechanisms may play an important role.
- Published
- 2020
223. Vitamin D inhibits Tissue Factor and CAMs expression in oxidized low-density lipoproteins-treated human endothelial cells by modulating NF-κB pathway
- Author
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Grazia Pellegrino, Laura Marra, Plinio Cirillo, Stefano Conte, Paolo Golino, Andrea Morello, Giovanni Cimmino, Cimmino, Giovanni, Morello, Andrea, Conte, Stefano, Pellegrino, Grazia, Marra, Laura, Golino, Paolo, Cirillo, Plinio, Cimmino, G., Morello, A., Conte, S., Pellegrino, G., Marra, L., Golino, P., and Cirillo, P.
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0301 basic medicine ,Adhesion molecule ,Human Umbilical Vein Endothelial Cell ,Chromosomal translocation ,Pharmacology ,Thromboplastin ,03 medical and health sciences ,chemistry.chemical_compound ,Tissue factor ,0302 clinical medicine ,Western blot ,Human Umbilical Vein Endothelial Cells ,medicine ,Vitamin D and neurology ,Humans ,Vitamin D ,Endothelial Cell ,medicine.diagnostic_test ,Cell adhesion molecule ,Chemistry ,NF-kappa B ,Endothelial Cells ,Thrombosis ,NF-κB ,Vitamins ,Atherosclerosis ,Cardiovascular disease ,In vitro ,Pathophysiology ,Lipoproteins, LDL ,030104 developmental biology ,Cell Adhesion Molecule ,Atherosclerosi ,Thrombosi ,Receptors, Calcitriol ,Cell Adhesion Molecules ,Oxidation-Reduction ,030217 neurology & neurosurgery ,Human ,Signal Transduction - Abstract
Epidemiologic studies have clearly demonstrated the correlation existing between Vitamin D (Vit. D) deficiency and increased risk of developing cardiovascular disease, suggesting that it might have a protective role in this clinical setting. Although many experimental studies have investigated the molecular mechanisms by which Vit. D might exert these effects, its potential role in protecting against athero-thrombosis is still partially unknown. We have investigated whether Vit. D might exert anti athero-thombotic effects by preventing expression of adhesion molecules (CAMs) and Tissue Factor (TF), molecules involved in atherothrombotic pathophysiology, in oxLDL stimulated endothelial cells (HUVEC). Moreover, we have investigated whether Vit. D effects might be due to the NF-kB modulation. HUVEC cultivated in medium enriched with Vit. D (10 nM) were stimulated with oxLDL (50 μg/ml). TF gene (RT-PCR), protein (Western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. Similarly, CAMs gene (RT-PCR), surface expression (FACS) and soluble values (ELISA) were measured. NF-kB translocation was also investigated. Vit. D significantly reduced TF gene as well protein expression and procoagulant activity in oxLDL-treated HUVEC. Similar effects were observed for CAMs. These effects were associated with Vit. D modulation of NF-κB pathway. This study, although in vitro, indicate that Vit. D has protective effect on endothelial cells by inhibiting expression of TF and CAMs, proteins involved in atherothrombotic pathophysiology. Further studies will be necessary to translate these findings to a clinical scenario to better define the potential therapeutical role of Vit. D supplementation in the management of cardiovascular disease in patients with Vit. D deficiency.
- Published
- 2020
224. Effects of Hypobaric Hypoxia on Endothelial Function and Adiponectin Levels in Airforce Aviators
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Bruno Trimarco, Grazia Pellegrino, Alberto Autore, Fabio Morgagni, Giovanni Cimmino, Mario Grittani, Andrea Morello, Stefano Conte, Plinio Cirillo, Grittani, Mario, Pellegrino, Grazia, Conte, Stefano, Morello, Andrea, Autore, Alberto, Cimmino, Giovanni, Trimarco, Bruno, Morgagni, Fabio, Cirillo, Plinio, Grittani, M., Pellegrino, G., Conte, S., Morello, A., Autore, A., Cimmino, G., Trimarco, B., Morgagni, F., and Cirillo, P.
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Adult ,Male ,medicine.medical_specialty ,Physiology ,endothelial function ,Internal medicine ,medicine ,Humans ,Hypoxia ,Saliva ,Adiponectin ,adiponectin ,Mechanism (biology) ,business.industry ,Public Health, Environmental and Occupational Health ,General Medicine ,hypobaric hypoxia ,Pathophysiology ,United States ,military pilot ,Vasodilation ,Pilots ,military pilots ,Endocrinology ,Military Personnel ,Hypobaric hypoxia ,Endothelium, Vascular ,business ,Function (biology) ,Biomarkers - Abstract
Grittani, Mario, Grazia Pellegrino, Stefano Conte, Andrea Morello, Alberto Autore, Giovanni Cimmino, Bruno Trimarco, Fabio Morgagni, and Plinio Cirillo. Effects of hypobaric hypoxia on endothelial function and adiponectin levels in airforce aviators. High Alt Med Biol 00:000-000, 2019. Background: Hypobaric hypoxia (HH) increases the risk of high altitude-related illnesses (HARI). The pathophysiological mechanism(s) involved are still partially unknown. Altered vascular reactivity as consequence of endothelial dysfunction during HH might play a role in this phenomenon. Adiponectin exerts protective effect on cardiovascular system since it modulates NO release, antagonizing endothelial dysfunction. Aims of this study, performed in a selected population of airforce aviators, were (1) to investigate whether exposure to acute HH might be associated with endothelial dysfunction and (2) to evaluate whether adiponectin might be involved in modulating this phenomenon. Methods: Twenty aviators were exposed to acute HH in a hypobaric chamber by simulating altitude of 8000 and then 6000 m for 2 hours. Vascular reactivity was evaluated by the EndoPAT test immediately before and after the HH; salivary and blood adiponectin levels were measured. Results: EndoPAT performed immediately after HH divided pilots in two groups: 12 pilots with preserved vascular reactivity and 8 pilots with reduction of vascular reactivity, indicating that HH exposure might cause endothelial dysfunction. Salivary and blood adiponectin levels increased post-HH in a time-dependent manner in all aviators, but the significant increase was observed only in those with preserved vascular reactivity suggesting that HH stimulated release of adiponectin that, in turn, by exerting a protective effect, might reduce endothelial dysfunction. Conclusions: Acute HH may cause endothelial dysfunction due, at least in part, to reduced release of adiponectin. This phenomenon might be involved in pathophysiology of HARI..
- Published
- 2019
225. Colchicine reduces platelet aggregation by modulating cytoskeleton rearrangement via inhibition of cofilin and LIM domain kinase 1
- Author
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Bruno Trimarco, Gaetano Calì, Roberta Tarallo, Grazia Pellegrino, Stefano Conte, Francesco S. Loffredo, Plinio Cirillo, Andrea Morello, Giovanni Cimmino, Paolo Golino, Nicola De Luca, Cimmino, Giovanni, Tarallo, Roberta, Conte, Stefano, Morello, Andrea, Pellegrino, Grazia, Loffredo, Francesco S., Calì, Gaetano, De Luca, Nicola, Golino, Paolo, Trimarco, Bruno, Cirillo, Plinio, and Loffredo, Francesco
- Subjects
Platelets ,Blood Platelets ,0301 basic medicine ,Cofilin 1 ,Platelet Aggregation ,Lim Kinase ,Physiology ,Protein subunit ,Protein Kinase Inhibitor ,macromolecular substances ,030204 cardiovascular system & hematology ,LIMK1 ,03 medical and health sciences ,chemistry.chemical_compound ,Myosin-Light-Chain Phosphatase ,Cytoskeleton Colchicine Platelets ,0302 clinical medicine ,Microtubule ,Humans ,Platelet activation ,Phosphorylation ,Cytoskeleton ,Protein Kinase Inhibitors ,Pharmacology ,biology ,Platelet Aggregation Inhibitor ,Platelet ,Lim Kinases ,Colchicine ,Cofilin ,Cell biology ,Adenosine diphosphate ,030104 developmental biology ,Tubulin ,chemistry ,biology.protein ,Blood Platelet ,Molecular Medicine ,Platelet Aggregation Inhibitors ,Human ,Signal Transduction - Abstract
Introduction Platelets activation/aggregation with subsequent thrombus formation is the main event in the pathophysiology of acute coronary syndrome. Once activated, platelets show an extensive cytoskeleton rearrangement that leads to recruitment of additional platelets to finally cause haemostatic plug formation. Thus, the cytoskeleton plays a pivotal role in this phenomenon. Colchicine (COLC) is an anti-inflammatory drug proven to reduce major cardiovascular events in patients with coronary artery disease. The molecular mechanisms by which COLC exerts these protective effects remain partially still unknown. Since COLC causes disruption of tubulin, a component of cell cytoskeleton, we investigated whether this drug might interfere with platelet aggregation by acting on cytoskeleton rearrangement. Methods and results Platelets isolated from healthy volunteers were activated with Adenosine Diphosphate (ADP, 20 μM) Collagen (COLL, 60 μg/ml) and Thrombin Activating Receptor Peptide (TRAP 25 μM) with/without COLC 10 μM pretreatment. After stimulus, aggregation was measured by light aggregometry overtime. Microtubules structure was assessed by immunohistochemistry and key proteins involved in regulation of actin-filament assembly and contractility such as Myosin Phosphatase Targeting subunit (MYPT), LIM domain kinase 1(LIMK1) and cofilin were evaluated by Western Blot analysis. Colchicine pretreatment significantly blunted ADP/COLL/TRAP-induced platelet aggregation (up to 40%). COLC effects appeared mediated by microtubules depolymerization and cytoskeleton disarrangement associated to inactivation of MYPT and LIMK1 that finally interfered with cofilin activity. Conclusions Our data indicate that colchicine exerts anti-platelet effects in vitro via inhibition of key proteins involved in cytoskeleton rearrangement, suggesting that its beneficial cardiovascular properties may be due, at least in part, to an inhibitory effect of platelet activity.
- Published
- 2018
226. Relationship between Pregnancy-associated Plasma Protein-A and tissue factor levels in the coronary circulation of patients with acute coronary syndrome
- Author
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Giovanni Cimmino, Andrea Morello, Paolo Golino, Bruno Trimarco, Plinio Cirillo, Stefano Conte, Grazia Pellegrino, Cirillo, Plinio, Cimmino, Giovanni, Conte, Stefano, Pellegrino, Grazia, Morello, Andrea, Golino, Paolo, and Trimarco, Bruno
- Subjects
Male ,medicine.medical_specialty ,Acute coronary syndrome ,Pregnancy-associated plasma protein A ,030204 cardiovascular system & hematology ,Coronary Angiography ,Thromboplastin ,03 medical and health sciences ,Coronary circulation ,Tissue factor ,0302 clinical medicine ,Text mining ,Pregnancy ,Coronary Circulation ,Internal medicine ,medicine ,Humans ,Pregnancy-Associated Plasma Protein-A ,030212 general & internal medicine ,Acute Coronary Syndrome ,Pregnancy Associated Plasma Protein-A Coronary Circulation, ACS, Tissue factor ,business.industry ,medicine.disease ,medicine.anatomical_structure ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business ,Biomarkers - Abstract
In recent years, Pregnancy-associated Plasma Protein-A (PAPP-A), a metalloproteinase originally identified in the plasma of pregnant women and then found in both men and women, has been studied for its potential involvement in cardiovascular disease. Several studies have indicated that PAPP-A might be considered as a marker of Acute Coronary Syndromes (ACS) able to predict outcome of patients with this clinical presentation. We have recently demonstrated that PAPP-A is able to induce TF expression in endothelial cells in vitro, suggesting an active involvement of this metalloproteinase in thrombotic events. We found that transcoronary PAPP-A levels were significantly higher in ACS-NSTEMI patients as compared to patients with SCAD and that elevated PAPP-A concentrations were associated with higher rate of TF consumption. results of this study permit for the first time to speculate that this metalloproteinase, does not represent only an independent risk factor for adverse cardiovascular or a marker of disease to obtain and early diagnosis of ACS, but it rather might play an “active” role in the pathophysiology of ACS as an effector molecule able to induce thrombus formation in the coronary circulation.
- Published
- 2018
227. Practice change in chronic conditions care: an appraisal of theories
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R. Doug McEvoy, Jennifer Tieman, Sharon Lawn, Melanie Harris, Andrea Morello, Julie Ratcliffe, Malcolm Battersby, Harris, Melanie, Lawn, Sharon J, Morello, Andrea, Battersby, Malcolm W, Ratcliffe, Julie, McEvoy, R Doug, and Tieman, Jennifer J
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Chronic conditions ,Normalization process theory ,Process management ,Chronic care management ,Care provision ,Health administration ,03 medical and health sciences ,0302 clinical medicine ,Nursing ,Health care ,Humans ,Medicine ,030212 general & internal medicine ,theories ,Chronic care ,business.industry ,030503 health policy & services ,Health Policy ,Nursing research ,Practice change ,Theories ,chronic conditions ,Evidence-Based Practice ,Chronic Disease ,Guideline Adherence ,Implementation research ,Diffusion of Innovation ,practice change ,0305 other medical science ,business ,Delivery of Health Care ,Research Article - Abstract
Background: Management of chronic conditions can be complex and burdensome for patients and complex and costly for health systems. Outcomes could be improved and costs reduced if proven clinical interventions were better implemented, but the complexity of chronic care services appears to make clinical change particularly challenging. Explicit use of theories may improve the success of clinical change in this area of care provision. Whilst theories to support implementation of practice change are apparent in the broad healthcare arena, the most applicable theories for the complexities of practice change in chronic care have not yet been identified. Methods: We developed criteria to review the usefulness of change implementation theories for informing chronic care management and applied them to an existing list of theories used more widely in healthcare. Results: Criteria related to the following characteristics of chronic care: breadth of the field; multi-disciplinarity; micro, meso and macro program levels; need for field-specific research on implementation requirements; and need for measurement. Six theories met the criteria to the greatest extent: the Consolidate Framework for Implementation Research; Normalization Process Theory and its extension General Theory of Implementation; two versions of the Promoting Action on Research Implementation in Health Services framework and Sticky Knowledge. None fully met all criteria. Involvement of several care provision organizations and groups, involvement of patients and carers, and policy level change are not well covered by most theories. However, adaptation may be possible to include multiple groups including patients and carers, and separate theories may be needed on policy change. Ways of qualitatively assessing theory constructs are available but quantitative measures are currently partial and under development for all theories. Conclusions: Theoretical bases are available to structure clinical change research in chronic condition care. Theories will however need to be adapted and supplemented to account for the particular features of care in this field, particularly in relation to involvement of multiple organizations and groups, including patients, and in relation to policy influence. Quantitative measurement of theory constructs may present difficulties. Refereed/Peer-reviewed
- Published
- 2017
228. Scalable Atomic Arrays for Spin-Based Quantum Computers in Silicon.
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Jakob AM, Robson SG, Firgau HR, Mourik V, Schmitt V, Holmes D, Posselt M, Mayes ELH, Spemann D, McCallum JC, Morello A, and Jamieson DN
- Abstract
Semiconductor spin qubits combine excellent quantum performance with the prospect of manufacturing quantum devices using industry-standard metal-oxide-semiconductor (MOS) processes. This applies also to ion-implanted donor spins, which further afford exceptional coherence times and large Hilbert space dimension in their nuclear spin. Here multiple strategies are demonstrated and integrated to manufacture scale-up donor-based quantum computers.
31 PF2 molecule implants are used to triple the placement certainty compared to31 P ions, while attaining 99.99% confidence in detecting the implant. Similar confidence is retained by implanting heavier atoms such as123 Sb and209 Bi, which represent high-dimensional qudits for quantum information processing, while Sb2 molecules enable deterministic formation of closely-spaced qudits. The deterministic formation of regular arrays of donor atoms with 300 nm spacing is demonstrated, using step-and-repeat implantation through a nano aperture. These methods cover the full gamut of technological requirements for the construction of donor-based quantum computers in silicon., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)- Published
- 2024
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229. Tomography of entangling two-qubit logic operations in exchange-coupled donor electron spin qubits.
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Stemp HG, Asaad S, Blankenstein MRV, Vaartjes A, Johnson MAI, Mądzik MT, Heskes AJA, Firgau HR, Su RY, Yang CH, Laucht A, Ostrove CI, Rudinger KM, Young K, Blume-Kohout R, Hudson FE, Dzurak AS, Itoh KM, Jakob AM, Johnson BC, Jamieson DN, and Morello A
- Abstract
Scalable quantum processors require high-fidelity universal quantum logic operations in a manufacturable physical platform. Donors in silicon provide atomic size, excellent quantum coherence and compatibility with standard semiconductor processing, but no entanglement between donor-bound electron spins has been demonstrated to date. Here we present the experimental demonstration and tomography of universal one- and two-qubit gates in a system of two weakly exchange-coupled electrons, bound to single phosphorus donors introduced in silicon by ion implantation. We observe that the exchange interaction has no effect on the qubit coherence. We quantify the fidelity of the quantum operations using gate set tomography (GST), and we use the universal gate set to create entangled Bell states of the electrons spins, with fidelity 91.3 ± 3.0%, and concurrence 0.87 ± 0.05. These results form the necessary basis for scaling up donor-based quantum computers., (© 2024. The Author(s).)
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- 2024
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230. E-Cigarettes induce expression of procoagulant tissue factor in cultivated human endothelial cells.
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Cirillo P, Morello M, Titolo G, Marra L, Morello A, De Rosa G, Cozzolino D, Sugraliyev A, and Cimmino G
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Background: E-cigarettes (ECIG) are proposed as an alternative for regular tobacco users with less dangerous effects for health. Several studies demonstrated that ECIG exert deleterious cardiovascular effects and promote platelet dependent thrombosis. However, ECIG role on Tissue Factor-dependent thrombosis is still unknown. Dysfunctional endothelial cells (ECs) are known to express Tissue Factor (TF) on their surface. Aim of the present study was to investigate whether ECIG might promote TF expression in ECs, shifting them to a pro thrombotic phenotype., Methods: Human Umbilical Vein Endothelial Cells (HUVEC) were incubated with increasing doses of ECIG (commercially available and mix of propylene glycol/vegetable glycerine/nicotine 18 mg/mL) up to 1.8 mg/mL. TF gene expression and protein levels were assessed at different time points by Real Time PCR and Western Blot, respectively. TF surface expression and activity were also measured by FACS analysis and coagulation assay. Finally, NF-kB translocation was investigated as possible mechanism of action. Potential protective effects by Rosuvastatin were also investigated., Results: ECIG significantly increased TF expression at both gene and protein levels in a time and dose dependent manner. Surface expression and procoagulant activity were increased as well. These phenomena appeared modulated by the NF-κB pathway. Rosuvastatin reduced ECIG effects on TF-mRNA., Conclusions: Although in vitro, we indicate that ECIG promote a pro thrombotic phenotype in ECs via expression of functional TF. Data of the present study permit to shed a brighter light on the still partially unresolved issue about the role of ECIG in development of cardiovascular diseases suggesting that they might represent a potential risk factor for thrombotic cardiovascular events., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2024
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231. Strong microwave squeezing above 1 Tesla and 1 Kelvin.
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Vaartjes A, Kringhøj A, Vine W, Day T, Morello A, and Pla JJ
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Squeezed states of light have been used extensively to increase the precision of measurements, from the detection of gravitational waves to the search for dark matter. In the optical domain, high levels of vacuum noise squeezing are possible due to the availability of low loss optical components and high-performance squeezers. At microwave frequencies, however, limitations of the squeezing devices and the high insertion loss of microwave components make squeezing vacuum noise an exceptionally difficult task. Here we demonstrate direct measurements of high levels of microwave squeezing. We use an ultra-low loss setup and weakly-nonlinear kinetic inductance parametric amplifiers to squeeze microwave noise 7.8(2) dB below the vacuum level. The amplifiers exhibit a resilience to magnetic fields and permit the demonstration of large squeezing levels inside fields of up to 2 T. Finally, we exploit the high critical temperature of our amplifiers to squeeze a warm thermal environment, achieving vacuum level noise at a temperature of 1.8 K. These results enable experiments that combine squeezing with magnetic fields and permit quantum-limited microwave measurements at elevated temperatures, significantly reducing the complexity and cost of the cryogenic systems required for such experiments., (© 2024. The Author(s).)
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- 2024
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232. Latched detection of zeptojoule spin echoes with a kinetic inductance parametric oscillator.
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Vine W, Kringhøj A, Savytskyi M, Parker D, Schenkel T, Johnson BC, McCallum JC, Morello A, and Pla JJ
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When strongly pumped at twice their resonant frequency, nonlinear resonators develop a high-amplitude intracavity field, a phenomenon known as parametric self-oscillations. The boundary over which this instability occurs can be extremely sharp and thereby presents an opportunity for realizing a detector. Here, we operate such a device based on a superconducting microwave resonator whose nonlinearity is engineered from kinetic inductance. The device indicates the absorption of low-power microwave wavepackets by transitioning to a self-oscillating state. Using calibrated pulses, we measure the detection efficiency to zeptojoule energy wavepackets. We then apply it to measurements of electron spin resonance, using an ensemble of
209 Bi donors in silicon that are inductively coupled to the resonator. We achieve a latched readout of the spin signal with an amplitude that is five hundred times greater than the underlying spin echoes.- Published
- 2024
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233. High-fidelity spin qubit operation and algorithmic initialization above 1 K.
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Huang JY, Su RY, Lim WH, Feng M, van Straaten B, Severin B, Gilbert W, Dumoulin Stuyck N, Tanttu T, Serrano S, Cifuentes JD, Hansen I, Seedhouse AE, Vahapoglu E, Leon RCC, Abrosimov NV, Pohl HJ, Thewalt MLW, Hudson FE, Escott CC, Ares N, Bartlett SD, Morello A, Saraiva A, Laucht A, Dzurak AS, and Yang CH
- Abstract
The encoding of qubits in semiconductor spin carriers has been recognized as a promising approach to a commercial quantum computer that can be lithographically produced and integrated at scale
1-10 . However, the operation of the large number of qubits required for advantageous quantum applications11-13 will produce a thermal load exceeding the available cooling power of cryostats at millikelvin temperatures. As the scale-up accelerates, it becomes imperative to establish fault-tolerant operation above 1 K, at which the cooling power is orders of magnitude higher14-18 . Here we tune up and operate spin qubits in silicon above 1 K, with fidelities in the range required for fault-tolerant operations at these temperatures19-21 . We design an algorithmic initialization protocol to prepare a pure two-qubit state even when the thermal energy is substantially above the qubit energies and incorporate radiofrequency readout to achieve fidelities up to 99.34% for both readout and initialization. We also demonstrate single-qubit Clifford gate fidelities up to 99.85% and a two-qubit gate fidelity of 98.92%. These advances overcome the fundamental limitation that the thermal energy must be well below the qubit energies for the high-fidelity operation to be possible, surmounting a main obstacle in the pathway to scalable and fault-tolerant quantum computation., (© 2024. The Author(s).)- Published
- 2024
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234. Navigating the 16-dimensional Hilbert space of a high-spin donor qudit with electric and magnetic fields.
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Fernández de Fuentes I, Botzem T, Johnson MAI, Vaartjes A, Asaad S, Mourik V, Hudson FE, Itoh KM, Johnson BC, Jakob AM, McCallum JC, Jamieson DN, Dzurak AS, and Morello A
- Abstract
Efficient scaling and flexible control are key aspects of useful quantum computing hardware. Spins in semiconductors combine quantum information processing with electrons, holes or nuclei, control with electric or magnetic fields, and scalable coupling via exchange or dipole interaction. However, accessing large Hilbert space dimensions has remained challenging, due to the short-distance nature of the interactions. Here, we present an atom-based semiconductor platform where a 16-dimensional Hilbert space is built by the combined electron-nuclear states of a single antimony donor in silicon. We demonstrate the ability to navigate this large Hilbert space using both electric and magnetic fields, with gate fidelity exceeding 99.8% on the nuclear spin, and unveil fine details of the system Hamiltonian and its susceptibility to control and noise fields. These results establish high-spin donors as a rich platform for practical quantum information and to explore quantum foundations., (© 2024. The Author(s).)
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- 2024
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235. Jellybean Quantum Dots in Silicon for Qubit Coupling and On-Chip Quantum Chemistry.
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Wang Z, Feng M, Serrano S, Gilbert W, Leon RCC, Tanttu T, Mai P, Liang D, Huang JY, Su Y, Lim WH, Hudson FE, Escott CC, Morello A, Yang CH, Dzurak AS, Saraiva A, and Laucht A
- Abstract
The small size and excellent integrability of silicon metal-oxide-semiconductor (SiMOS) quantum dot spin qubits make them an attractive system for mass-manufacturable, scaled-up quantum processors. Furthermore, classical control electronics can be integrated on-chip, in-between the qubits, if an architecture with sparse arrays of qubits is chosen. In such an architecture qubits are either transported across the chip via shuttling or coupled via mediating quantum systems over short-to-intermediate distances. This paper investigates the charge and spin characteristics of an elongated quantum dot-a so-called jellybean quantum dot-for the prospects of acting as a qubit-qubit coupler. Charge transport, charge sensing, and magneto-spectroscopy measurements are performed on a SiMOS quantum dot device at mK temperature and compared to Hartree-Fock multi-electron simulations. At low electron occupancies where disorder effects and strong electron-electron interaction dominate over the electrostatic confinement potential, the data reveals the formation of three coupled dots, akin to a tunable, artificial molecule. One dot is formed centrally under the gate and two are formed at the edges. At high electron occupancies, these dots merge into one large dot with well-defined spin states, verifying that jellybean dots have the potential to be used as qubit couplers in future quantum computing architectures., (© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.)
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- 2023
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236. In situ amplification of spin echoes within a kinetic inductance parametric amplifier.
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Vine W, Savytskyi M, Vaartjes A, Kringhøj A, Parker D, Slack-Smith J, Schenkel T, Mølmer K, McCallum JC, Johnson BC, Morello A, and Pla JJ
- Abstract
The use of superconducting microresonators together with quantum-limited Josephson parametric amplifiers has enhanced the sensitivity of pulsed electron spin resonance (ESR) measurements by more than four orders of magnitude. So far, the microwave resonators and amplifiers have been designed as separate components due to the incompatibility of Josephson junction-based devices with magnetic fields. This has produced complex spectrometers and raised technical barriers toward adoption of the technique. Here, we circumvent this issue by coupling an ensemble of spins directly to a weakly nonlinear and magnetic field-resilient superconducting microwave resonator. We perform pulsed ESR measurements with a 1-pL mode volume containing 6 × 10
7 spins and amplify the resulting signals within the device. When considering only those spins that contribute to the detected signals, we find a sensitivity of [Formula: see text] for a Hahn echo sequence at a temperature of 400 mK. In situ amplification is demonstrated at fields up to 254 mT, highlighting the technique's potential for application under conventional ESR operating conditions.- Published
- 2023
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237. An electrically driven single-atom "flip-flop" qubit.
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Savytskyy R, Botzem T, Fernandez de Fuentes I, Joecker B, Pla JJ, Hudson FE, Itoh KM, Jakob AM, Johnson BC, Jamieson DN, Dzurak AS, and Morello A
- Abstract
The spins of atoms and atom-like systems are among the most coherent objects in which to store quantum information. However, the need to address them using oscillating magnetic fields hinders their integration with quantum electronic devices. Here, we circumvent this hurdle by operating a single-atom "flip-flop" qubit in silicon, where quantum information is encoded in the electron-nuclear states of a phosphorus donor. The qubit is controlled using local electric fields at microwave frequencies, produced within a metal-oxide-semiconductor device. The electrical drive is mediated by the modulation of the electron-nuclear hyperfine coupling, a method that can be extended to many other atomic and molecular systems and to the hyperpolarization of nuclear spin ensembles. These results pave the way to the construction of solid-state quantum processors where dense arrays of atoms can be controlled using only local electric fields.
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- 2023
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238. On-demand electrical control of spin qubits.
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Gilbert W, Tanttu T, Lim WH, Feng M, Huang JY, Cifuentes JD, Serrano S, Mai PY, Leon RCC, Escott CC, Itoh KM, Abrosimov NV, Pohl HJ, Thewalt MLW, Hudson FE, Morello A, Laucht A, Yang CH, Saraiva A, and Dzurak AS
- Abstract
Once called a 'classically non-describable two-valuedness' by Pauli, the electron spin forms a qubit that is naturally robust to electric fluctuations. Paradoxically, a common control strategy is the integration of micromagnets to enhance the coupling between spins and electric fields, which, in turn, hampers noise immunity and adds architectural complexity. Here we exploit a switchable interaction between spins and orbital motion of electrons in silicon quantum dots, without a micromagnet. The weak effects of relativistic spin-orbit interaction in silicon are enhanced, leading to a speed up in Rabi frequency by a factor of up to 650 by controlling the energy quantization of electrons in the nanostructure. Fast electrical control is demonstrated in multiple devices and electronic configurations. Using the electrical drive, we achieve a coherence time T
2,Hahn ≈ 50 μs, fast single-qubit gates with Tπ/2 = 3 ns and gate fidelities of 99.93%, probed by randomized benchmarking. High-performance all-electrical control improves the prospects for scalable silicon quantum computing., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)- Published
- 2023
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239. Uric Acid Induces a Proatherothrombotic Phenotype in Human Endothelial Cells by Imbalancing the Tissue Factor/Tissue Factor Pathway Inhibitor Pathway.
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Cimmino G, Conte S, Marra L, Morello A, Morello M, De Rosa G, Pepe M, Sugraliyev A, Golino P, and Cirillo P
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- Humans, Uric Acid pharmacology, Uric Acid metabolism, NF-kappa B metabolism, Fibrinolytic Agents, Inflammasomes metabolism, Human Umbilical Vein Endothelial Cells metabolism, Thromboplastin genetics, Thromboplastin metabolism, Cardiovascular Diseases metabolism
- Abstract
Background: Several evidence show that elevated plasma levels of uric acid (UA) are associated with the increased risk of developing atherothrombotic cardiovascular events. Hyperuricemia is a risk factor for endothelial dysfunction (ED). ED is involved in the pathophysiology of atherothrombosis since dysfunctional cells lose their physiological, antithrombotic properties. We have investigated whether UA might promote ED by modulating the tissue factor (TF)/TF pathway inhibitor (TFPI) balance by finally changing the antithrombotic characteristics of endothelial cells., Methods: Human umbilical vein endothelial cells were incubated with increasing doses of UA (up to 9 mg/dL). TF gene and protein expressions were evaluated by real-time polymerase chain reaction (PCR) and Western blot. Surface expression and procoagulant activity were assessed by FACS (fluorescence activated cell sorting) analysis and coagulation assay. The mRNA and protein levels of TFPI were measured by real-time PCR and Western blot. The roles of inflammasome and nuclear factor-κB (NF-κB) as possible mechanism(s) of action of the UA on TF/TFPI balance were also investigated., Results: UA significantly increased TF gene and protein levels, surface expression, and procoagulant activity. In parallel, TFPI levels were significantly reduced. The NF-κB pathways appeared to be involved in modulating these phenomena. Additionally, inflammasome might also play a role., Conclusion: The present in vitro study shows that one of the mechanisms by which high levels of UA contribute to ED might be the imbalance between TF/TFPI levels in endothelial cells, shifting them to a nonphysiological, prothrombotic phenotype. These UA effects might hypothetically explain, at least in part, the relationship observed between elevated plasma levels of UA and cardiovascular events., Competing Interests: None declared., (Thieme. All rights reserved.)
- Published
- 2023
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240. Vitamin D Inhibits IL-6 Pro-Atherothrombotic Effects in Human Endothelial Cells: A Potential Mechanism for Protection against COVID-19 Infection?
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Cimmino G, Conte S, Morello M, Pellegrino G, Marra L, Morello A, Nicoletti G, De Rosa G, Golino P, and Cirillo P
- Abstract
Background: Thrombosis with cardiovascular involvement is a crucial complication in COVID-19 infection. COVID-19 infects the host by the angiotensin converting enzyme-2 receptor (ACE2r), which is expressed in endothelial cells too. Thus, COVID-related thrombotic events might be due to endothelial dysfunction. IL-6 is one of the main cytokines involved in the COVID-19 inflammatory storm. Some evidence indicates that Vitamin D (VitD) has a protective role in COVID-19 patients, but the molecular mechanisms involved are still debated. Thus, we investigated the effect of VitD on Tissue Factor and adhesion molecules (CAMs) in IL-6-stimulated endothelial cells (HUVEC). Moreover, we evaluated levels of the ACE2r gene and proteins. Finally, we studied the modulation of NF-kB and STAT3 pathways., Methods: HUVEC cultivated in VitD-enriched medium were stimulated with IL-6 (0.5 ng/mL). The TF gene (RT-PCR), protein (Western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. Similarly, CAMs soluble values (ELISA) and ACE2r (RT-PCR and Western blot) levels were assessed. NF-kB and STAT3 modulation (Western blot) were also investigated., Results: VitD significantly reduced TF expression at both gene and protein levels as well as TF-procoagulant activity in IL-6-treated HUVEC. Similar effects were observed for CAMs and ACE2r expression. IL-6 modulates these effects by regulating NF-κB and STAT3 pathways., Conclusions: IL-6 induces endothelial dysfunction with TF and CAMs expression via upregulation of ACE2r. VitD prevented these IL-6 deleterious effects. Thus, it might be speculated that this is one of the hypothetical mechanism(s) by which VitD exerts its beneficial effects in COVID-19 infection.
- Published
- 2022
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241. Precision tomography of a three-qubit donor quantum processor in silicon.
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Mądzik MT, Asaad S, Youssry A, Joecker B, Rudinger KM, Nielsen E, Young KC, Proctor TJ, Baczewski AD, Laucht A, Schmitt V, Hudson FE, Itoh KM, Jakob AM, Johnson BC, Jamieson DN, Dzurak AS, Ferrie C, Blume-Kohout R, and Morello A
- Abstract
Nuclear spins were among the first physical platforms to be considered for quantum information processing
1,2 , because of their exceptional quantum coherence3 and atomic-scale footprint. However, their full potential for quantum computing has not yet been realized, owing to the lack of methods with which to link nuclear qubits within a scalable device combined with multi-qubit operations with sufficient fidelity to sustain fault-tolerant quantum computation. Here we demonstrate universal quantum logic operations using a pair of ion-implanted31 P donor nuclei in a silicon nanoelectronic device. A nuclear two-qubit controlled-Z gate is obtained by imparting a geometric phase to a shared electron spin4 , and used to prepare entangled Bell states with fidelities up to 94.2(2.7)%. The quantum operations are precisely characterized using gate set tomography (GST)5 , yielding one-qubit average gate fidelities up to 99.95(2)%, two-qubit average gate fidelity of 99.37(11)% and two-qubit preparation/measurement fidelities of 98.95(4)%. These three metrics indicate that nuclear spins in silicon are approaching the performance demanded in fault-tolerant quantum processors6 . We then demonstrate entanglement between the two nuclei and the shared electron by producing a Greenberger-Horne-Zeilinger three-qubit state with 92.5(1.0)% fidelity. Because electron spin qubits in semiconductors can be further coupled to other electrons7-9 or physically shuttled across different locations10,11 , these results establish a viable route for scalable quantum information processing using donor nuclear and electron spins., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)- Published
- 2022
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242. Deterministic Shallow Dopant Implantation in Silicon with Detection Confidence Upper-Bound to 99.85% by Ion-Solid Interactions.
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Jakob AM, Robson SG, Schmitt V, Mourik V, Posselt M, Spemann D, Johnson BC, Firgau HR, Mayes E, McCallum JC, Morello A, and Jamieson DN
- Abstract
Silicon chips containing arrays of single dopant atoms can be the material of choice for classical and quantum devices that exploit single donor spins. For example, group-V donors implanted in isotopically purified
28 Si crystals are attractive for large-scale quantum computers. Useful attributes include long nuclear and electron spin lifetimes of31 P, hyperfine clock transitions in209 Bi or electrically controllable123 Sb nuclear spins. Promising architectures require the ability to fabricate arrays of individual near-surface dopant atoms with high yield. Here, an on-chip detector electrode system with 70 eV root-mean-square noise (≈20 electrons) is employed to demonstrate near-room-temperature implantation of single 14 keV31 P+ ions. The physics model for the ion-solid interaction shows an unprecedented upper-bound single-ion-detection confidence of 99.85 ± 0.02% for near-surface implants. As a result, the practical controlled silicon doping yield is limited by materials engineering factors including surface gate oxides in which detected ions may stop. For a device with 6 nm gate oxide and 14 keV31 P+ implants, a yield limit of 98.1% is demonstrated. Thinner gate oxides allow this limit to converge to the upper-bound. Deterministic single-ion implantation can therefore be a viable materials engineering strategy for scalable dopant architectures in silicon devices., (© 2021 The Authors. Advanced Materials published by Wiley-VCH GmbH.)- Published
- 2022
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243. Quantum-coherent nanoscience.
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Heinrich AJ, Oliver WD, Vandersypen LMK, Ardavan A, Sessoli R, Loss D, Jayich AB, Fernandez-Rossier J, Laucht A, and Morello A
- Abstract
For the past three decades nanoscience has widely affected many areas in physics, chemistry and engineering, and has led to numerous fundamental discoveries, as well as applications and products. Concurrently, quantum science and technology has developed into a cross-disciplinary research endeavour connecting these same areas and holds burgeoning commercial promise. Although quantum physics dictates the behaviour of nanoscale objects, quantum coherence, which is central to quantum information, communication and sensing, has not played an explicit role in much of nanoscience. This Review describes fundamental principles and practical applications of quantum coherence in nanoscale systems, a research area we call quantum-coherent nanoscience. We structure this Review according to specific degrees of freedom that can be quantum-coherently controlled in a given nanoscale system, such as charge, spin, mechanical motion and photons. We review the current state of the art and focus on outstanding challenges and opportunities unlocked by the merging of nanoscience and coherent quantum operations., (© 2021. Springer Nature Limited.)
- Published
- 2021
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244. Conditional quantum operation of two exchange-coupled single-donor spin qubits in a MOS-compatible silicon device.
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Ma Dzik MT, Laucht A, Hudson FE, Jakob AM, Johnson BC, Jamieson DN, Itoh KM, Dzurak AS, and Morello A
- Abstract
Silicon nanoelectronic devices can host single-qubit quantum logic operations with fidelity better than 99.9%. For the spins of an electron bound to a single-donor atom, introduced in the silicon by ion implantation, the quantum information can be stored for nearly 1 second. However, manufacturing a scalable quantum processor with this method is considered challenging, because of the exponential sensitivity of the exchange interaction that mediates the coupling between the qubits. Here we demonstrate the conditional, coherent control of an electron spin qubit in an exchange-coupled pair of
31 P donors implanted in silicon. The coupling strength, J = 32.06 ± 0.06 MHz, is measured spectroscopically with high precision. Since the coupling is weaker than the electron-nuclear hyperfine coupling A ≈ 90 MHz which detunes the two electrons, a native two-qubit controlled-rotation gate can be obtained via a simple electron spin resonance pulse. This scheme is insensitive to the precise value of J, which makes it suitable for the scale-up of donor-based quantum computers in silicon that exploit the metal-oxide-semiconductor fabrication protocols commonly used in the classical electronics industry.- Published
- 2021
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245. Coherent electrical control of a single high-spin nucleus in silicon.
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Asaad S, Mourik V, Joecker B, Johnson MAI, Baczewski AD, Firgau HR, Mądzik MT, Schmitt V, Pla JJ, Hudson FE, Itoh KM, McCallum JC, Dzurak AS, Laucht A, and Morello A
- Subjects
- Electromagnetic Phenomena, Electrons, Quantum Dots chemistry, Models, Theoretical, Silicon chemistry
- Abstract
Nuclear spins are highly coherent quantum objects. In large ensembles, their control and detection via magnetic resonance is widely exploited, for example, in chemistry, medicine, materials science and mining. Nuclear spins also featured in early proposals for solid-state quantum computers
1 and demonstrations of quantum search2 and factoring3 algorithms. Scaling up such concepts requires controlling individual nuclei, which can be detected when coupled to an electron4-6 . However, the need to address the nuclei via oscillating magnetic fields complicates their integration in multi-spin nanoscale devices, because the field cannot be localized or screened. Control via electric fields would resolve this problem, but previous methods7-9 relied on transducing electric signals into magnetic fields via the electron-nuclear hyperfine interaction, which severely affects nuclear coherence. Here we demonstrate the coherent quantum control of a single123 Sb (spin-7/2) nucleus using localized electric fields produced within a silicon nanoelectronic device. The method exploits an idea proposed in 196110 but not previously realized experimentally with a single nucleus. Our results are quantitatively supported by a microscopic theoretical model that reveals how the purely electrical modulation of the nuclear electric quadrupole interaction results in coherent nuclear spin transitions that are uniquely addressable owing to lattice strain. The spin dephasing time, 0.1 seconds, is orders of magnitude longer than those obtained by methods that require a coupled electron spin to achieve electrical driving. These results show that high-spin quadrupolar nuclei could be deployed as chaotic models, strain sensors and hybrid spin-mechanical quantum systems using all-electrical controls. Integrating electrically controllable nuclei with quantum dots11,12 could pave the way to scalable, nuclear- and electron-spin-based quantum computers in silicon that operate without the need for oscillating magnetic fields.- Published
- 2020
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246. A silicon quantum-dot-coupled nuclear spin qubit.
- Author
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Hensen B, Wei Huang W, Yang CH, Wai Chan K, Yoneda J, Tanttu T, Hudson FE, Laucht A, Itoh KM, Ladd TD, Morello A, and Dzurak AS
- Abstract
Single nuclear spins in the solid state are a potential future platform for quantum computing
1-3 , because they possess long coherence times4-6 and offer excellent controllability7 . Measurements can be performed via localized electrons, such as those in single atom dopants8,9 or crystal defects10-12 . However, establishing long-range interactions between multiple dopants or defects is challenging13,14 . Conversely, in lithographically defined quantum dots, tunable interdot electron tunnelling allows direct coupling of electron spin-based qubits in neighbouring dots15-20 . Moreover, the compatibility with semiconductor fabrication techniques21 may allow for scaling to large numbers of qubits in the future. Unfortunately, hyperfine interactions are typically too weak to address single nuclei. Here we show that for electrons in silicon metal-oxide-semiconductor quantum dots the hyperfine interaction is sufficient to initialize, read out and control single29 Si nuclear spins. This approach combines the long coherence times of nuclear spins with the flexibility and scalability of quantum dot systems. We demonstrate high-fidelity projective readout and control of the nuclear spin qubit, as well as entanglement between the nuclear and electron spins. Crucially, we find that both the nuclear spin and electron spin retain their coherence while moving the electron between quantum dots. Hence we envision long-range nuclear-nuclear entanglement via electron shuttling3 . Our results establish nuclear spins in quantum dots as a powerful new resource for quantum processing.- Published
- 2020
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247. Gate-based single-shot readout of spins in silicon.
- Author
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West A, Hensen B, Jouan A, Tanttu T, Yang CH, Rossi A, Gonzalez-Zalba MF, Hudson F, Morello A, Reilly DJ, and Dzurak AS
- Abstract
Electron spins in silicon quantum dots provide a promising route towards realizing the large number of coupled qubits required for a useful quantum processor
1-7 . For the implementation of quantum algorithms and error detection8-10 , qubit measurements are ideally performed in a single shot, which is presently achieved using on-chip charge sensors, capacitively coupled to the quantum dots11 . However, as the number of qubits is increased, this approach becomes impractical due to the footprint and complexity of the charge sensors, combined with the required proximity to the quantum dots12 . Alternatively, the spin state can be measured directly by detecting the complex impedance of spin-dependent electron tunnelling between quantum dots13-15 . This can be achieved using radiofrequency reflectometry on a single gate electrode defining the quantum dot itself15-19 , significantly reducing the gate count and architectural complexity, but thus far it has not been possible to achieve single-shot spin readout using this technique. Here, we detect single electron tunnelling in a double quantum dot and demonstrate that gate-based sensing can be used to read out the electron spin state in a single shot, with an average readout fidelity of 73%. The result demonstrates a key step towards the readout of many spin qubits in parallel, using a compact gate design that will be needed for a large-scale semiconductor quantum processor.- Published
- 2019
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248. E-learning for self-management support: introducing blended learning for graduate students - a cohort study.
- Author
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Munro V, Morello A, Oster C, Redmond C, Vnuk A, Lennon S, and Lawn S
- Subjects
- Chronic Disease therapy, Cohort Studies, Humans, Schools, Health Occupations, Self-Management, South Australia, Students, Medical, Education, Distance, Education, Graduate methods, Physical Therapy Specialty education
- Abstract
Background: E-learning allows delivery of education in many diverse settings and researchers have demonstrated it can be as effective as learning conducted in traditional face-to-face settings. However, there are particular practices and skills needed in the area of providing patient self-management support (SMS), that may not be achievable online. The aim of this study was to compare three approaches in the training of university students regarding the preparation of a Chronic Condition Self-Management Care Plan: 1) traditional face-to-face delivery of SMS training, 2) an e-learning approach and 3) a blended approach (combining e-learning and face-to-face teaching)., Methods: Graduate entry physiotherapy students and medical students at Flinders University were recruited. Depending on the cohort, students were either exposed to traditional face-to-face training, e-learning or a blended model. Outcomes were compared between the three groups. We measured adherence to care plan processes in the preparation of an assessment piece using the Flinders Program Chronic Care Self Management tools. A total of 183 care plans were included (102 traditional, 52 blended, 29 e-learning,). All students submitted the Flinders Program Chronic Care Plan for university assessment and these were later assessed for quality by researchers. The submission was also assigned a consumer engagement score and a global competence score as these are integral to successful delivery of SMS and represent the patient perspective., Results: The blended group performed significantly better than the traditional group in quality use of the Flinders Program tools: Problem and Goals (P < 0.0001). They also performed significantly better in the total care plan score (P < 0.0001) and engagement score (P < 0.0001). There was no significant difference between the groups for the Partners in Health tool., Conclusions: In this pilot study, the blended learning model was a more effective method for teaching self-management skills than the traditional group, as assessed in the development of a chronic condition self-management care plan. We anticipate that future research with identical groups of students would yield similar results but in the meantime, academics can have confidence that blended learning is at least as effective as traditional learning methods.
- Published
- 2018
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249. Quantum search on a single-atom qudit.
- Author
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Morello A
- Published
- 2018
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250. Silicon quantum processor with robust long-distance qubit couplings.
- Author
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Tosi G, Mohiyaddin FA, Schmitt V, Tenberg S, Rahman R, Klimeck G, and Morello A
- Abstract
Practical quantum computers require a large network of highly coherent qubits, interconnected in a design robust against errors. Donor spins in silicon provide state-of-the-art coherence and quantum gate fidelities, in a platform adapted from industrial semiconductor processing. Here we present a scalable design for a silicon quantum processor that does not require precise donor placement and leaves ample space for the routing of interconnects and readout devices. We introduce the flip-flop qubit, a combination of the electron-nuclear spin states of a phosphorus donor that can be controlled by microwave electric fields. Two-qubit gates exploit a second-order electric dipole-dipole interaction, allowing selective coupling beyond the nearest-neighbor, at separations of hundreds of nanometers, while microwave resonators can extend the entanglement to macroscopic distances. We predict gate fidelities within fault-tolerance thresholds using realistic noise models. This design provides a realizable blueprint for scalable spin-based quantum computers in silicon.Quantum computers will require a large network of coherent qubits, connected in a noise-resilient way. Tosi et al. present a design for a quantum processor based on electron-nuclear spins in silicon, with electrical control and coupling schemes that simplify qubit fabrication and operation.
- Published
- 2017
- Full Text
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