170 results on '"L. Patthey"'
Search Results
2. Probing multi-spinon excitations outside of the two-spinon continuum in the antiferromagnetic spin chain cuprate Sr2CuO3
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J. Schlappa, U. Kumar, K. J. Zhou, S. Singh, M. Mourigal, V. N. Strocov, A. Revcolevschi, L. Patthey, H. M. Rønnow, S. Johnston, and T. Schmitt
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Science - Abstract
Quasi-1D magnetic insulators are very attractive for searching and studying quantum many-body phenomena. Here the authors report the four-spinon excitations in quasi-1D spin-chain cuprate Sr2CuO3 by momentum resolved RIXS technique which provides a new route for the creation of magnetic excitations in 1D materials.
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- 2018
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3. High resolution soft X-ray spectrometer for FEL characterisation and optimisation
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C. Arrell, V. Thominet, Y. Arbelo, U. Wagner, N. Gradwohl, E. Prat, L. Patthey, and R. Follath
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A high resolution (∆E < 100 meV) single shot spectrometer for the soft X-ray at SwissFEL is reported. Use of this high fidelity single shot data to develop new modes of operations of operation is described.
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- 2022
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4. Strain wave pathway to semiconductor-to-metal transition revealed by time-resolved X-ray powder diffraction
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Simon Ebner, Majed Chergui, Hervé Cailleau, Paul Beaud, Henrik T. Lemke, Eric Collet, Gerhard Ingold, Alexei Bosak, Andrej Babic, Dmitry Ozerov, S. Vetter, Laurent Cario, Roman Bertoni, Laurent Guérin, Pavle Juranić, Michael Wulff, Giulia F. Mancini, Vincent Esposito, T. Zmofing, Alexander Roland Oggenfuss, Aldo Mozzanica, Shin-ichi Ohkoshi, Yunpei Deng, Maciej Lorenc, Ivan Usov, Serhane Zerdane, Matteo Levantino, Akos Schreiber, Marco Cammarata, Roman Mankowsky, Elzbieta Trzop, Rolf Follath, P. Böhler, Céline Mariette, S. Redford, C. Svetina, Olivier Hernandez, Leonardo Sala, A. Volte, X. Dong, L. Patthey, Hiroko Tokoro, V. Ta Phuoc, B. Lépine, A. Keller, Etienne Janod, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), The University of Tokyo (UTokyo), Université de Tsukuba = University of Tsukuba, SwissFEL, Paul Scherrer Institut, SLAC National Accelerator Laboratory (SLAC), Stanford University, Ecole Polytechnique Fédérale de Lausanne (EPFL), European Synchrotron Radiation Facility (ESRF), IM‐LED LIA, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes (UN)-Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Tours (UT)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE30-0018,ELASTICA,Cooperativité Elastique Photo-Induite dans des Matériaux Bistables avec Changement de Volume(2016), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours-Centre National de la Recherche Scientifique (CNRS)
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Diffraction ,Phase transition ,Materials science ,Electronic properties and materials ,Bistability ,Science ,FOS: Physical sciences ,General Physics and Astronomy ,Physics::Optics ,Applied Physics (physics.app-ph) ,02 engineering and technology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,Condensed Matter::Materials Science ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,[CHIM]Chemical Sciences ,010306 general physics ,[PHYS]Physics [physics] ,Condensed Matter - Materials Science ,Multidisciplinary ,Condensed matter physics ,Materials Science (cond-mat.mtrl-sci) ,Physics - Applied Physics ,General Chemistry ,Acoustic wave ,021001 nanoscience & nanotechnology ,3. Good health ,Phase transitions and critical phenomena ,Picosecond ,Femtosecond ,0210 nano-technology ,Ultrashort pulse ,Powder diffraction - Abstract
Thanks to the remarkable developments of ultrafast science, one of today's challenges is to modify material state by controlling with a light pulse the coherent motions that connect two different phases. Here we show how strain waves, launched by electronic and structural precursor phenomena, determine a macroscopic transformation pathway for the semiconducting-to-metal transition with large volume change in bistable Ti$_3$O$_5$ nanocrystals. Femtosecond powder X-ray diffraction allowed us to quantify the structural deformations associated with the photoinduced phase transition on relevant time scales. We monitored the early intra-cell distortions around absorbing metal dimers, but also long range crystalline deformations dynamically governed by acoustic waves launched at the laser-exposed Ti$_3$O$_5$ surface. We rationalize these observations with a simplified elastic model, demonstrating that a macroscopic transformation occurs concomitantly with the propagating acoustic wavefront on the picosecond timescale, several decades earlier than the subsequent thermal processes governed by heat diffusion., 30 pages (including supplementary text), 5 main figures, 9 supplementary figures; corrected author list
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- 2020
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5. Optical design of the Athos beamlines at SwissFEL
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R. Follath, Ulrich Wagner, L. Patthey, and U. Flechsig
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Physics ,business.industry ,Free-electron laser ,Grating ,Photon energy ,Undulator ,law.invention ,Optics ,Beamline ,law ,Achromatic lens ,business ,Beam (structure) ,Monochromator - Abstract
The Paul Scherrer Institut is currently constructing Athos, its second Free Electron Laser with a photon energy range from 250 eV to 1900 eV and pulse energies up to 8 mJ. A single soft X-ray beamline is attached to the undulator section and distributes the radiation into three branches. The beamline design is based on a variable line space spherical grating monochromator with a grating chamber and two retractable distribution mirrors. An achromatic focusing with individual KB-mirror systems downstream of the exit slits focus the beam to the endstations. The stations can operate alternatively without interfering with each other.
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- 2019
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6. Inspecting adaptive optics with at-wavelength wavefront metrology
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Frank Seiboth, J. Krempaský, Ulrich Wagner, C. Svetina, Matthew Seaberg, Uwe Flechsig, Frieder Koch, Ladislav Mikeš, Patrik Vagovic, Christoph Rau, Darren Batey, Shashidhara Marathe, Silvia Cipiccia, A. Jaggi, L. Patthey, and Christian David
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Physics ,Wavefront ,business.industry ,Physics::Optics ,Zone plate ,Ptychography ,law.invention ,Metrology ,Radius of curvature (optics) ,Optics ,law ,Profilometer ,business ,Adaptive optics ,Swiss Light Source - Abstract
Preserving the coherence and wavefront of a diffraction limited x-ray beam from the source to the experiment poses stringent quality requirements on the production processes for X-ray optics. In the near future this will require on-line and in-situ at-wavelength metrology for both, free electron lasers and diffraction limited storage rings. A compact and easy to move X-ray grating interferometry (XGI) setup has been implemented by the Beamline Optics Group at PSI in order to characterize x-ray optical components by determining the aberrations from reconstructing the x-ray wavefront. The XGI setup was configured for measurements in the moire mode and tested with focusing optic at Swiss Light Source, Diamond Light Source and LCLS. In this paper measurements on a bendable toroidal mirror, a zone plate, a single and a stack of beryllium compound refractive lenses (CRL) are presented. From these measurements the focal position and quality of the beam spot in terms of wavefront distortions are determined by analysing the phase-signal obtained from the XGI measurement. In addition, using a bendable toroidal mirror, we directly compare radius of curvature measurements obtained from XGI data with data from a long-trace profilometer, and compare the CRL wavefront distortions with data obtained by ptychography.
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- 2018
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7. Atomically Precise Lateral Modulation of a Two-Dimensional Electron Liquid in Anatase TiO
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Z, Wang, Z, Zhong, S, McKeown Walker, Z, Ristic, J-Z, Ma, F Y, Bruno, S, Riccò, G, Sangiovanni, G, Eres, N C, Plumb, L, Patthey, M, Shi, J, Mesot, F, Baumberger, and M, Radovic
- Abstract
Engineering the electronic band structure of two-dimensional electron liquids (2DELs) confined at the surface or interface of transition metal oxides is key to unlocking their full potential. Here we describe a new approach to tailoring the electronic structure of an oxide surface 2DEL demonstrating the lateral modulation of electronic states with atomic scale precision on an unprecedented length scale comparable to the Fermi wavelength. To this end, we use pulsed laser deposition to grow anatase TiO
- Published
- 2017
8. Atomically Precise Lateral Modulation of a Two-Dimensional Electron Liquid in Anatase TiO2 Thin Films
- Author
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S. McKeown Walker, Felix Baumberger, Zhicheng Zhong, Junzhang Ma, Nicholas C. Plumb, S. Riccò, Ming Shi, Zhiming Wang, Gyula Eres, Flavio Y. Bruno, Milan Radovic, Giorgio Sangiovanni, L. Patthey, Zoran Ristić, and Joël Mesot
- Subjects
Anatase ,Angle-resolved photoemission spectroscopy ,Materials science ,Lateral patterning ,FOS: Physical sciences ,Bioengineering ,02 engineering and technology ,Electronic structure ,ddc:500.2 ,01 natural sciences ,Molecular physics ,Pulsed laser deposition ,Condensed Matter - Strongly Correlated Electrons ,Condensed Matter::Materials Science ,Optics ,0103 physical sciences ,General Materials Science ,Two-dimensional electron liquid ,Thin film ,010306 general physics ,Electronic band structure ,Condensed Matter - Materials Science ,Strongly Correlated Electrons (cond-mat.str-el) ,business.industry ,Mechanical Engineering ,Electron liquid ,Materials Science (cond-mat.mtrl-sci) ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Density of states ,Titanium dioxide ,0210 nano-technology ,business ,Surface reconstruction - Abstract
Engineering the electronic band structure of two-dimensional electron liquids (2DELs) confined at the surface or interface of transition metal oxides is key to unlocking their full potential. Here we describe a new approach to tailoring the electronic structure of an oxide surface 2DEL demonstrating the lateral modulation of electronic states with atomic scale precision on an unprecedented length scale comparable to the Fermi wavelength. To this end, we use pulsed laser deposition to grow anatase TiO2 films terminated by a (1 x 4) in-plane surface reconstruction. Employing photo-stimulated chemical surface doping we induce 2DELs with tunable carrier densities that are confined within a few TiO2 layers below the surface. Subsequent in-situ angle resolved photoemission experiments demonstrate that the (1 x 4) surface reconstruction provides a periodic lateral perturbation of the electron liquid. This causes strong backfolding of the electronic bands, opening of unidirectional gaps and a saddle point singularity in the density of states near the chemical potential.
- Published
- 2017
9. NaFe0.56Cu0.44As: A Pnictide Insulating Phase Induced by On-Site Coulomb Interaction
- Author
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Milan Radovic, L. Patthey, Yu Song, Nicholas C. Plumb, Nan Xu, B. Q. Lv, Joël Mesot, C. E. Matt, Pengcheng Dai, Chongde Cao, Federico Bisti, J. Park, Tian Shang, Ming Shi, Andriy H. Nevidomskyy, and Junzhang Ma
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Superconductivity ,Materials science ,Condensed matter physics ,Band gap ,Mott insulator ,General Physics and Astronomy ,02 engineering and technology ,Electronic structure ,021001 nanoscience & nanotechnology ,01 natural sciences ,Excited state ,0103 physical sciences ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Density functional theory ,010306 general physics ,0210 nano-technology ,Ground state - Abstract
In the studies of iron pnictides, a key question is whether their bad-metal state from which the superconductivity emerges lies in close proximity with a magnetically ordered insulating phase. Recently, it was found that at low temperatures, the heavily Cu-doped ${\mathrm{NaFe}}_{1\ensuremath{-}x}{\mathrm{Cu}}_{x}\mathrm{As}$ ($xg0.3$) iron pnictide is an insulator with long-range antiferromagnetic order, similar to the parent compound of cuprates but distinct from all other iron pnictides. Using angle-resolved photoemission spectroscopy, we determined the momentum-resolved electronic structure of ${\mathrm{NaFe}}_{1\ensuremath{-}x}{\mathrm{Cu}}_{x}\mathrm{As}$ ($x=0.44$) and identified that its ground state is a narrow-gap insulator. Combining the experimental results with density functional theory (DFT) and $\mathrm{DFT}+U$ calculations, our analysis reveals that the on-site Coulombic (Hubbard) and Hund's coupling energies play crucial roles in the formation of the band gap about the chemical potential. We propose that at finite temperatures, charge carriers are thermally excited from the Cu-As-like valence band into the conduction band, which is of Fe $3d$-like character. With increasing temperature, the number of electrons in the conduction band becomes larger and the hopping energy between Fe sites increases, and finally the long-range antiferromagnetic order is destroyed at $Tg{T}_{N}$. Our study provides a basis for investigating the evolution of the electronic structure of a Mott insulator transforming into a bad metallic phase and eventually forming a superconducting state in iron pnictides.
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- 2016
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10. Phase fluctuations and the absence of topological defects in a photo-excited charge-ordered nickelate
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A. P. Sorini, Yulin Chen, M. C. Langner, Brian Moritz, William F. Schlotter, Takao Sasagawa, Robert W. Schoenlein, Joseph Robinson, Robert G. Moore, Y. F. Kung, D. H. Lu, Steven L. Johnson, Oleg Krupin, Wei-Sheng Lee, Michael Först, L. Patthey, Robert A. Kaindl, Zhi-Xun Shen, Joshua J. Turner, David A. Reis, Giacomo Coslovich, Alexander F. Kemper, Patrick S. Kirchmann, B. Huber, Zahid Hussain, Nils Huse, Yi-De Chuang, D.-H. Lee, Mariano Trigo, Yiwen Zhu, Dionisio Doering, Thomas P. Devereaux, Shuyun Zhou, Ming Yi, and Peter Denes
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Quantum phase transition ,Physics ,Multidisciplinary ,Condensed matter physics ,Strongly Correlated Electrons (cond-mat.str-el) ,Relaxation (NMR) ,Degrees of freedom (physics and chemistry) ,General Physics and Astronomy ,Thermal fluctuations ,FOS: Physical sciences ,Charge (physics) ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology ,Topological defect ,Condensed Matter - Strongly Correlated Electrons ,Phase (matter) ,ddc:500 ,Order of magnitude - Abstract
The dynamics of an order parameter's amplitude and phase determines the collective behaviour of novel states emerged in complex materials. Time- and momentum-resolved pump-probe spectroscopy, by virtue of its ability to measure material properties at atomic and electronic time scales and create excited states not accessible by the conventional means can decouple entangled degrees of freedom by visualizing their corresponding dynamics in the time domain. Here, combining time-resolved femotosecond optical and resonant x-ray diffraction measurements on striped La1.75Sr0.25NiO4, we reveal unforeseen photo-induced phase fluctuations of the charge order parameter. Such fluctuations preserve long-range order without creating topological defects, unlike thermal phase fluctuations near the critical temperature in equilibrium10. Importantly, relaxation of the phase fluctuations are found to be an order of magnitude slower than that of the order parameter's amplitude fluctuations, and thus limit charge order recovery. This discovery of new aspect to phase fluctuation provides more holistic view for the importance of phase in ordering phenomena of quantum matter., Comment: 23 pages, 6 figures. Published version can be found at Nature Communications 3, 838 (2012)
- Published
- 2016
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11. Persistence of magnetic order in a highly excited Cu2+ state in CuO
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Y.-D. Chuang, Ming Yi, Urs Staub, Joshua J. Turner, Mariano Trigo, Peter Denes, Gerhard Ingold, R. A. De Souza, William F. Schlotter, Andrew T. Boothroyd, Valerio Scagnoli, E. Möhr-Vorobeva, Patrick S. Kirchmann, Dionisio Doering, Andrin Caviezel, D. H. Lu, Paul Beaud, Bernard Delley, Oleg Krupin, Wei-Sheng Lee, L. Patthey, Steven L. Johnson, Zahid Hussain, D. Prabhakaran, Robert G. Moore, and Z.-X. Shen
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Diffraction ,Optical pumping ,Materials science ,Condensed matter physics ,Excited state ,Electron ,Atomic physics ,Condensed Matter Physics ,Electronic band structure ,Ultrashort pulse ,Spectral line ,Excitation ,Electronic, Optical and Magnetic Materials - Abstract
We use ultrafast resonant x-ray diffraction to study the magnetic order in CuO under conditions of high electronic excitation. By measuring changes in the spectral shape of the Cu2+ magnetic (1/2 0 â1/2) reflection we investigate how an intense optical pump pulse perturbs the electronic and magnetic states. We observe an energy shift in the magnetic resonance at short times after the pump pulse. This shift is compared with expectations from band structure calculations at different electronic temperatures. This spectral line shift indicates that although the electrons are heated to effective electron temperatures far above TN on a time scale faster than the experimental resolution, magnetic order persists in this highly excited state for several hundred femtoseconds. © 2014 American Physical Society.
- Published
- 2016
12. NaFe_{0.56}Cu_{0.44}As: A Pnictide Insulating Phase Induced by On-Site Coulomb Interaction
- Author
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C E, Matt, N, Xu, Baiqing, Lv, Junzhang, Ma, F, Bisti, J, Park, T, Shang, Chongde, Cao, Yu, Song, Andriy H, Nevidomskyy, Pengcheng, Dai, L, Patthey, N C, Plumb, M, Radovic, J, Mesot, and M, Shi
- Abstract
In the studies of iron pnictides, a key question is whether their bad-metal state from which the superconductivity emerges lies in close proximity with a magnetically ordered insulating phase. Recently, it was found that at low temperatures, the heavily Cu-doped NaFe_{1-x}Cu_{x}As (x0.3) iron pnictide is an insulator with long-range antiferromagnetic order, similar to the parent compound of cuprates but distinct from all other iron pnictides. Using angle-resolved photoemission spectroscopy, we determined the momentum-resolved electronic structure of NaFe_{1-x}Cu_{x}As (x=0.44) and identified that its ground state is a narrow-gap insulator. Combining the experimental results with density functional theory (DFT) and DFT+U calculations, our analysis reveals that the on-site Coulombic (Hubbard) and Hund's coupling energies play crucial roles in the formation of the band gap about the chemical potential. We propose that at finite temperatures, charge carriers are thermally excited from the Cu-As-like valence band into the conduction band, which is of Fe 3d-like character. With increasing temperature, the number of electrons in the conduction band becomes larger and the hopping energy between Fe sites increases, and finally the long-range antiferromagnetic order is destroyed at TT_{N}. Our study provides a basis for investigating the evolution of the electronic structure of a Mott insulator transforming into a bad metallic phase and eventually forming a superconducting state in iron pnictides.
- Published
- 2016
13. Ultrafast resonant soft x-ray diffraction dynamics of the charge density wave inTbTe3
- Author
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Oleg Krupin, Wei-Sheng Lee, Joshua J. Turner, T. P. Devereaux, Y.-D. Chuang, Mariano Trigo, William F. Schlotter, Alexander F. Kemper, Donghui Lu, David A. Reis, Ph. Hering, Zahid Hussain, T. Benson, Robert G. Moore, Jiun-Haw Chu, Peter Denes, Dionisio Doering, Ian R. Fisher, Ming Yi, Zhi-Xun Shen, P. S. Kirchman, G. Hays, and L. Patthey
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Diffraction ,Physics ,Phase transition ,Condensed matter physics ,Phonon ,Charge density ,Nanotechnology ,Fermi surface ,02 engineering and technology ,Electron ,021001 nanoscience & nanotechnology ,01 natural sciences ,Amplitude ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,Charge density wave - Abstract
Understanding the emergence of collective behavior in correlated electron systems remains at the forefront of modern condensed matter physics. Disentangling the degrees of freedom responsible for collective behavior can lead to insights into the microscopic origins of emergent properties and phase transitions. Utilizing an optical pump, resonant soft x-ray diffraction probe we are able to track, in real time, the dynamics of the charge density wave (CDW) in ${\mathrm{TbTe}}_{3}$, a model system that violates traditional views of a Fermi surface nested CDW. We observe coherent oscillations corresponding to the CDW amplitude mode at $2.4$ THz and a coherent optical phonon mode at $\ensuremath{\sim}1.7\phantom{\rule{0.16em}{0ex}}\mathrm{THz}$. We show how such observations reveal the anisotropic energy optimization between in-plane Te charge density modulations and the three-dimensional lattice coupling.
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- 2016
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14. Spin-orbital separation in the quasi-one-dimensional Mott insulator Sr2CuO3
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K.J. Zhou, J.E. van den Brink, Henrik M. Rønnow, Maurits W. Haverkort, L. Patthey, Martin Mourigal, Surjeet Singh, Vladimir N. Strocov, J. Schlappa, Claude Monney, Satoshi Nishimoto, Jean-Sébastien Caux, Liviu Hozoi, Krzysztof Wohlfeld, A. Revcolevschi, T. Schmitt, and Quantum Condensed Matter Theory (ITFA, IoP, FNWI)
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Physics ,Multidisciplinary ,Orbiton ,Condensed matter physics ,Mott insulator ,02 engineering and technology ,Electron ,Mott scattering ,X-Ray-Scattering ,021001 nanoscience & nanotechnology ,Quantum number ,01 natural sciences ,Spinon ,Azimuthal quantum number ,Srcuo2 ,Atomic orbital ,spin orbital separation, orbitons, RIXS, resonant inelastic x ray scattering ,Excitations ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,Atomic physics ,010306 general physics ,0210 nano-technology ,Charge Separation - Abstract
When viewed as an elementary particle, the electron has spin and charge. When binding to the atomic nucleus, it also acquires an angular momentum quantum number corresponding to the quantized atomic orbital it occupies. Even if electrons in solids form bands and delocalize from the nuclei, in Mott insulators they retain their three fundamental quantum numbers spin, charge and orbital. The hallmark of one dimensional physics is a breaking up of the elementary electron into its separate degrees of freedom. The separation of the electron into independent quasiparticles that carry either spin spinons or charge holons was first observed fifteen years ago. Here we report observation of the separation of the orbital degree of freedom orbiton using resonant inelastic X ray scattering on the one dimensional Mott insulator Sr2CuO3. We resolve an orbiton separating itself from spinons and propagating through the lattice as a distinct quasiparticle with a substantial dispersion in energy over momentum, of about 0.2 electronvolts, over nearly one Brillouin zone
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- 2012
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15. Atomically controlled quantum chains hosting a Tomonaga–Luttinger liquid
- Author
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Ralph Claessen, J. Schäfer, S. Mietke, Xiaoyu Cui, René Matzdorf, M. Lochner, S. Meyer, A. Dollinger, C. Blumenstein, and L. Patthey
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Condensed Matter::Quantum Gases ,Surface (mathematics) ,Physics ,Condensed matter physics ,General Physics and Astronomy ,chemistry.chemical_element ,Germanium ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Spectral line ,chemistry ,Luttinger liquid ,Condensed Matter::Strongly Correlated Electrons ,Electrical conductor ,Quantum ,Quantum tunnelling - Abstract
The Tomonaga–Luttinger liquid model is the leading candidate for describing one-dimensional metallic conductors at low temperature. Yet, experimental evidence that it is valid is sketchy. Scanning tunnelling and photoemission spectra suggest that it does, in fact, describe the behaviour of chains of gold atoms self-assembled on the surface of germanium.
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- 2011
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16. Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr2IrO4
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M. Sikorski, Xuerong Liu, Joseph Robinson, S. Owada, John Hill, Mark Dean, Michael Först, Makina Yabashi, Tetsuo Katayama, C.-L. Chang, Sanghoon Song, Jungho Kim, J. G. Vale, Vivek Thampy, Yoshikazu Tanaka, Ayman Said, Lucas Huber, Roman Mankowsky, Bum Joon Kim, Michael Kozina, D. F. McMorrow, Yue Cao, Diling Zhu, Jian Liu, C. Rayan Serrao, Pavol Juhas, Henrik T. Lemke, Tadashi Togashi, Xiaoqian Chen, Simon Wall, James M. Glownia, Diego Casa, L. Patthey, Aymeric Robert, Roberto Alonso-Mori, and Optical Physics of Condensed Matter
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Superconductivity ,Magnetism ,FOS: Physical sciences ,02 engineering and technology ,Molecular Dynamics Simulation ,Iridium ,01 natural sciences ,Superconductivity (cond-mat.supr-con) ,Condensed Matter - Strongly Correlated Electrons ,0103 physical sciences ,HEISENBERG-ANTIFERROMAGNET ,General Materials Science ,OXIDES ,010306 general physics ,Physics ,Condensed Matter - Materials Science ,Magnetization dynamics ,Strongly Correlated Electrons (cond-mat.str-el) ,Condensed matter physics ,Condensed Matter - Superconductivity ,Mechanical Engineering ,Mott insulator ,Materials Science (cond-mat.mtrl-sci) ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,X-RAY-SCATTERING ,Photoexcitation ,Brillouin zone ,Magnetic Fields ,SPIN ,Mechanics of Materials ,Strontium ,Condensed Matter::Strongly Correlated Electrons ,0210 nano-technology ,Pseudogap ,Excitation - Abstract
Measuring how the magnetic correlations throughout the Brillouin zone evolve in a Mott insulator as charges are introduced dramatically improved our understanding of the pseudogap, non-Fermi liquids and high $T_C$ superconductivity. Recently, photoexcitation has been used to induce similarly exotic states transiently. However, understanding how these states emerge has been limited because of a lack of available probes of magnetic correlations in the time domain, which hinders further investigation of how light can be used to control the properties of solids. Here we implement magnetic resonant inelastic X-ray scattering at a free electron laser, and directly determine the magnetization dynamics after photo-doping the Mott insulator Sr$_2$IrO$_4$. We find that the non-equilibrium state 2~ps after the excitation has strongly suppressed long-range magnetic order, but hosts photo-carriers that induce strong, non-thermal magnetic correlations. The magnetism recovers its two-dimensional (2D) in-plane N\'eel correlations on a timescale of a few ps, while the three-dimensional (3D) long-range magnetic order restores over a far longer, fluence-dependent timescale of a few hundred ps. The dramatic difference in these two timescales, implies that characterizing the dimensionality of magnetic correlations will be vital in our efforts to understand ultrafast magnetic dynamics., Comment: 7 page, 4 figures; to appear in Nature Materials
- Published
- 2015
17. Electron scattering, charge order, and pseudogap physics inLa1.6−xNd0.4SrxCuO4: An angle-resolved photoemission spectroscopy study
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S. Pyon, Christian Matt, Ming Shi, Migaku Oda, Azzedine Bendounan, Nicholas C. Plumb, Oscar Tjernberg, H. Takagi, Martin Månsson, Sara Fatale, J.-S. Zhou, Naoki Momono, Marco Grioni, Stephen M Hayden, M. H. Berntsen, Johan Chang, T. Takayama, C. G. Fatuzzo, T. Kurosawa, J-Q Yan, Yasmine Sassa, L. Patthey, John B. Goodenough, Milan Radovic, O. J. Lipscombe, Joël Mesot, X. Shi, Elia Razzoli, Stéphane Pailhès, and V. Bitetta
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Physics ,Condensed matter physics ,Order (group theory) ,Charge (physics) ,Condensed Matter Physics ,Pseudogap ,Electron scattering ,Electronic, Optical and Magnetic Materials - Published
- 2015
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18. The new design of the THz streak camera at PSI
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R. Ivanov, I. Gorgisyan, Tetsuo Katayama, B. Monoszlai, Rafael Abela, Kanade Ogawa, Pavle Juranić, Christoph P. Hauri, Jia Liu, Claude Pradervand, Tadashi Togashi, Rasmus Ischebeck, Volker Schlott, S. Owada, Leonid Rivkin, Makina Yabashi, Peter Peier, Andrey L. Stepanov, L. Patthey, and Milan Radovic
- Subjects
Physics ,Photon ,business.industry ,Streak camera ,Terahertz radiation ,Instrumentation ,Free-electron laser ,Laser ,law.invention ,SACLA ,Optics ,law ,Femtosecond ,Optoelectronics ,business - Abstract
SwissFEL is the Free Electron Laser (FEL) facility under construction at the Paul Scherrer institute (PSI), aiming to provide users with X-ray pulses of lengths down to 2 femtoseconds at standard operation. The measurement of the length of the FEL pulses and their arrival time relative to the experimental laser is crucial for the pump-probe experiments carried out in such facilities. This work presents a new device that measures hard X-ray FEL pulses based on the THz streak camera concept. It describes the prototype setup called pulse arrival and length monitor (PALM) developed at PSI and tested in Spring-8 Angstrom Compact Free Electron Laser (SACLA) in Japan. Based on the first results obtained from the measurements, we introduce the new improved design of the second generation PALM setup that is currently under construction and will be used in SwissFEL photon diagnostics.
- Published
- 2015
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19. High-precision x-ray FEL pulse arrival time measurements at SACLA by a THz streak camera with Xe clusters
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Makina Yabashi, S. Owada, Rafael Abela, Christoph P. Hauri, Peter Peier, Pavle Juranić, I. Gorgisyan, Tetsuo Katayama, Tadashi Togashi, Jia Liu, L. Patthey, Andrey L. Stepanov, Rasmus Ischebeck, Claude Pradervand, B. Monoszlai, Leonid Rivkin, Kanade Ogawa, Milan Radovic, Volker Schlott, and R. Ivanov
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Photon ,Time Factors ,Xenon ,Light ,Physics::Optics ,Electrons ,law.invention ,SACLA ,Optics ,law ,Photography ,ddc:530 ,Physics ,Photons ,Streak camera ,business.industry ,Lasers ,X-Rays ,Free-electron laser ,Laser ,Atomic and Molecular Physics, and Optics ,Photon counting ,Pulse (physics) ,Femtosecond ,Physics::Accelerator Physics ,business ,Terahertz Radiation - Abstract
The accurate measurement of the arrival time of a hard X-ray free electron laser (FEL) pulse with respect to a laser is of utmost importance for pump-probe experiments proposed or carried out at FEL facilities around the world. This manuscript presents the latest device to meet this challenge, a THz streak camera using Xe gas clusters, capable of pulse arrival time measurements with an estimated accuracy of several femtoseconds. An experiment performed at SACLA demonstrates the performance of the device at photon energies between 5 and 10 keV with variable photon beam parameters. (C) 2014 Optical Society of America
- Published
- 2015
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20. Tuning the metal-insulator transition in NdNiO3 heterostructures via Fermi surface instability and spin fluctuations
- Author
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Zoran Ristić, Nan Xu, Elia Razzoli, Tanmoy Das, Ming Shi, L. Patthey, Nicholas C. Plumb, Milan Radovic, W. J. Kong, Joël Mesot, Rajendra S. Dhaka, C. E. Matt, Marisa Medarde, and Kapildeb Dolui
- Subjects
Materials science ,Condensed matter physics ,Strongly Correlated Electrons (cond-mat.str-el) ,Photoemission spectroscopy ,Physics ,Fermi level ,FOS: Physical sciences ,Fermi surface ,Angle-resolved photoemission spectroscopy ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Brillouin zone ,Condensed Matter - Strongly Correlated Electrons ,symbols.namesake ,symbols ,Quasiparticle ,Strongly correlated material ,Condensed Matter::Strongly Correlated Electrons ,Metal–insulator transition - Abstract
We employed {\it in-situ} pulsed laser deposition (PLD) and angle-resolved photoemission spectroscopy (ARPES) to investigate the mechanism of the metal-insulator transition (MIT) in NdNiO$_3$ (NNO) thin films, grown on NdGaO$_3$(110) and LaAlO$_3$(100) substrates. In the metallic phase, we observe three dimensional hole and electron Fermi surface (FS) pockets formed from strongly renormalized bands with well-defined quasiparticles. Upon cooling across the MIT in NNO/NGO sample, the quasiparticles lose coherence via a spectral weight transfer from near the Fermi level to localized states forming at higher binding energies. In the case of NNO/LAO, the bands are apparently shifted upward with an additional holelike pocket forming at the corner of the Brillouin zone. We find that the renormalization effects are strongly anisotropic and are stronger in NNO/NGO than NNO/LAO. Our study reveals that substrate-induced strain tunes the crystal field splitting, which changes the FS properties, nesting conditions, and spin-fluctuation strength, and thereby controls the MIT via the formation of an electronic order parameter with Q$_{AF}\sim$(1/4, 1/4, 1/4$\pm$$\delta$)., Comment: submitted
- Published
- 2015
21. Inspecting adaptive optics with at-wavelength wavefront metrology.
- Author
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J., Krempaský, F., Koch, P., Vagovič, L., Mikeš, A., Jaggi, C., Svetina, U., Flechsig, L., Patthey, S., Marathe, D., Batey, S., Cipiccia, C., Rau, F., Seiboth, M., Seaberg, C., David, and U. H., Wagner
- Published
- 2018
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22. Photon energy dependent photoemission study of La0.7Sr0.3MnO3
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Martin Neumann, L. Patthey, Ya. M. Mukovskii, Ming Shi, V. R. Galakhov, M. Falub, K. Hricovini, and J. Krempasky
- Subjects
Electronic correlation ,Chemistry ,Photoemission spectroscopy ,Inverse photoemission spectroscopy ,Angle-resolved photoemission spectroscopy ,Surfaces and Interfaces ,Interaction energy ,Electronic structure ,Photon energy ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Condensed Matter::Materials Science ,Materials Chemistry ,Density of states ,Condensed Matter::Strongly Correlated Electrons ,Atomic physics - Abstract
The electronic structure of the single crystal La0.7Sr0.3MnO3 in ferromagnetic metallic phase has been investigated by photoelectron spectroscopy. Valence band spectra were measured at 40 K for various photon energies, in the range of 45–70 eV. The Mn 3d partial density of states was derived from resonant photoemission near the Mn 3p–3d threshold. Besides the occupied 3d states, resonant photoemission data has provided information about the unoccupied 3d states. The value of the on-site Coulomb interaction strength (correlation energy) was estimated to be 6.7 eV.
- Published
- 2005
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23. Structural study of adsorption of isonicotinic acid and related molecules on rutile TiO2(110) II: XPS
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J Schnadt, J.N O’Shea, L Patthey, J Schiessling, J Krempaský, M Shi, N Mårtensson, and P.A Brühwiler
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Materials Chemistry ,Surfaces and Interfaces ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2003
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24. Addendum: The hard X-ray Photon Single-Shot Spectrometer of SwissFEL—initial characterization
- Author
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Carla David, Christof W. Schneider, P. Heimgartner, J. Rehanek, G. Seniutinas, U. Flechsig, V. Thominet, Mikako Makita, L. Patthey, Pavle Juranić, A. Rodriguez Fernandez, C. Pradervand, and P. Wiegand
- Subjects
Materials science ,Photon ,Optics ,Spectrometer ,business.industry ,Single shot ,X-ray ,Addendum ,business ,Instrumentation ,Mathematical Physics ,Characterization (materials science) - Published
- 2017
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25. The hard X-ray Photon Single-Shot Spectrometer of SwissFEL—initial characterization
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Carla David, P. Wiegand, P. Heimgartner, Mikako Makita, Pavle Juranić, L. Patthey, Christof W. Schneider, U. Flechsig, V. Thominet, A. Rodriguez Fernandez, G. Seniutinas, C. Pradervand, and J. Rehanek
- Subjects
0301 basic medicine ,Physics ,030103 biophysics ,Photon ,Spectral power distribution ,Spectrometer ,business.industry ,Photon energy ,01 natural sciences ,Electromagnetic radiation ,Spectral line ,03 medical and health sciences ,Optics ,Beamline ,0103 physical sciences ,Measuring instrument ,010306 general physics ,business ,Instrumentation ,Mathematical Physics - Abstract
SwissFEL requires the monitoring of the photon spectral distribution at a repetition rate of 100 Hz for machine optimization and experiment online diagnostics. The Photon Single Shot Spectrometer has been designed for the photon energy range of 4 keV to 12 keV provided by the Aramis beamline. It is capable of measuring the spectrum in a non-destructive manner, with an energy resolution of delta(E)/E = (2-5) x 10-5 over a bandwidth of 0.5% on a shot-to-shot basis. This article gives a detailed description about the technical challenges, structures, and considerations when building such a device, and to further enhance the performance of the spectrometer.
- Published
- 2017
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26. Valence band and core-level photoemission of Au/Ge(001): Band mapping and bonding sites
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A. Dollinger, Ralph Claessen, C. Blumenstein, P. Höpfner, Lenart Dudy, Xiaoyu Cui, J. Schäfer, T. E. Umbach, S. Meyer, and L. Patthey
- Subjects
Materials science ,Photoemission spectroscopy ,Fermi level ,Order (ring theory) ,Photon energy ,Condensed Matter Physics ,Molecular physics ,Spectral line ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,Chemical bond ,symbols ,Strongly correlated material ,Electronic band structure - Abstract
We have used photoemission spectroscopy in order to investigate the electronic states and chemical bonding related to Au induced atomic chains on the Ge(001) surface. Angle-resolved photoemission reveals two types of dispersions around the Fermi level whose intensities strongly depend on the incident photon energy. Around $h\ensuremath{\nu}=100\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$, the band structure is dominated by an electronlike band of mainly one-dimensional (1D) character, which shows Tomonaga-Luttinger-like power-law behavior in the $k$-integrated spectral function. In contrast, lower photon energies reveal a metallic holelike dispersion which resembles the Ge bulk structure with its heavy-hole, light-hole, and split-off branches. The Au $4f$ core-level spectra show two doublets indicating two different Au bonding sites, whereas the Ge $3d$ core-level shows two surface components and one bulk component.
- Published
- 2014
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27. Mixed Dimensionality of Confined Conducting Electrons in the Surface Region ofSrTiO3
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Marco Salluzzo, Ming Shi, Hubert Ebert, Martin Månsson, Jan Minár, M. Schulte, Nicholas C. Plumb, Milan Radovic, K. J. Zhou, Jürgen Braun, L. Patthey, Bernard Delley, J. Krempasky, C. E. Matt, Johan Juul Chang, Elia Razzoli, M. Falub, Thorsten Schmitt, and Joël Mesot
- Subjects
Surface (mathematics) ,Physics ,Condensed Matter - Materials Science ,Condensed matter physics ,Photoemission spectroscopy ,Doping ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,General Physics and Astronomy ,Fermi surface ,02 engineering and technology ,Electron ,021001 nanoscience & nanotechnology ,01 natural sciences ,Metal ,Surface conductivity ,Atomic orbital ,visual_art ,0103 physical sciences ,visual_art.visual_art_medium ,010306 general physics ,0210 nano-technology - Abstract
Using angle-resolved photoemission spectroscopy, we show that the recently-discovered surface state on SrTiO$_{3}$ consists of non-degenerate $t_{2g}$ states with different dimensional characters. While the $d_{xy}$ bands have quasi-2D dispersions with weak $k_{z}$ dependence, the lifted $d_{xz}$/$d_{yz}$ bands show 3D dispersions that differ significantly from bulk expectations and signal that electrons associated with those orbitals permeate the near-surface region. Like their more 2D counterparts, the size and character of the $d_{xz}$/$d_{yz}$ Fermi surface components are essentially the same for different sample preparations. Irradiating SrTiO$_{3}$ in ultrahigh vacuum is one method observed so far to induce the "universal" surface metallic state. We reveal that during this process, changes in the oxygen valence band spectral weight that coincide with the emergence of surface conductivity are disproportionate to any change in the total intensity of the O $1s$ core level spectrum. This signifies that the formation of the metallic surface goes beyond a straightforward chemical doping scenario and occurs in conjunction with profound changes in the initial states and/or spatial distribution of near-$E_{F}$ electrons in the surface region., Comment: Main text plus supplemental material. Total of 12 pages, 9 figures, 2 tables
- Published
- 2014
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28. Publisher's Note: Persistence of magnetic order in a highly excitedCu2+state in CuO [Phys. Rev. B89, 220401(R) (2014)]
- Author
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D. H. Lu, Mariano Trigo, Dionisio Doering, Zahid Hussain, R. A. De Souza, Steven L. Johnson, Peter Denes, D. Prabhakaran, Robert G. Moore, William F. Schlotter, Paul Beaud, Bernard Delley, L. Patthey, Y.-D. Chuang, Oleg Krupin, Wei-Sheng Lee, Urs Staub, Andrew T. Boothroyd, E. Möhr-Vorobeva, Patrick S. Kirchmann, Andrin Caviezel, Gerhard Ingold, Ming Yi, Joshua J. Turner, Valerio Scagnoli, and Z.-X. Shen
- Subjects
Physics ,Persistence (psychology) ,Condensed matter physics ,Magnetic order ,Excited state ,State (functional analysis) ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2014
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29. Nodal Landau Fermi-liquid quasiparticles in overdoped La1.77Sr0.23CuO4
- Author
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Henrik M. Rønnow, Yasmine Sassa, O. J. Lipscombe, Marco Grioni, Stéphane Pailhès, C. G. Fatuzzo, Ming Shi, L. Patthey, Oscar Tjernberg, Johan Juul Chang, Martin Månsson, Stephen M Hayden, and Joël Mesot
- Subjects
Physics ,Condensed matter physics ,Magnetoresistance ,Quantum oscillations ,Energy–momentum relation ,Electronic structure ,Condensed Matter Physics ,Spectral line ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Superconductivity ,Quantum mechanics ,Dispersion (optics) ,Quasiparticle ,Condensed Matter::Strongly Correlated Electrons ,Fermi liquid theory - Abstract
Nodal angle-resolved photoemission spectra taken on overdoped La1.77Sr0.23CuO4 are presented and analyzed. It is proven that the low-energy excitations are true Landau Fermi-liquid quasiparticles. We show that momentum and energy distribution curves can be analyzed self-consistently without quantitative knowledge of the bare band dispersion. Finally, by imposing Kramers-Kronig consistency on the self-energy Sigma, insight into the quasiparticle residue is gained. We conclude by comparing our results to quasiparticle properties extracted from thermodynamic, magnetoresistance, and high-field quantum oscillation experiments on overdoped Tl2Ba2CuO6+delta.
- Published
- 2014
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30. Insertion devices at the Swiss Light Source (phase I)
- Author
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Bruce D. Patterson, Thomas J. Schmidt, A. Imhof, Gerhard Ingold, Christoph Quitmann, L. Patthey, Rafael Abela, and Clemens Schulze-Briese
- Subjects
Physics ,Nuclear and High Energy Physics ,business.industry ,Wiggler ,Bremsstrahlung ,Synchrotron radiation ,Radiation ,Undulator ,Electromagnetic radiation ,Optics ,business ,Instrumentation ,Swiss Light Source ,Storage ring - Abstract
The insertion devices under construction for phase I of the Swiss Light Source (SLS) are described. Five undulators and one wiggler will be installed in four straight sections of the third generation 2.4 GeV SLS storage ring, under construction at the Paul Scherrer Institute. To provide undulator radiation in the energy range from 10 eV to 18 keV , both long period and short period, small gap undulators will be installed.
- Published
- 2001
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31. A monochromatized multiple energy laboratory UV source for k-space imaging
- Author
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J. Hayoz, Th. Pillo, E. Boschung, Philipp Aebi, Louis Schlapbach, and L. Patthey
- Subjects
Physics ,Range (particle radiation) ,Radiation ,Photon ,business.industry ,Photoemission spectroscopy ,Fermi energy ,Photon energy ,Condensed Matter Physics ,medicine.disease_cause ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Optics ,X-ray photoelectron spectroscopy ,law ,medicine ,Physical and Theoretical Chemistry ,business ,Spectroscopy ,Ultraviolet ,Monochromator - Abstract
A laboratory set-up for ultraviolet (UV) photoelectron spectroscopy combining a high intensity UV source and a toroidal UV monochromator, both being commercially available, is described. The source is modified in order to maximize the solid angle collected by the monochromator. Scanning its exit arm length allows for the optimization of the photon intensity as well as the energy resolution by minimizing the defocus term only. By using several different gases such as He, Ne or H2 one obtains a powerful tool to sample extended regions in k-space. Fermi energy maps are presented for Cu(110) in the photon energy range from 10.2 to 48.3 eV. As a result of the variable photon energy an actual zooming into the well-known Shockley surface state is possible.
- Published
- 1998
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32. Anomalous diffraction effect on the surface core-level photoemission from Si(001)2 × 1-Cs surface
- Author
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Tadashi Abukawa, L. Patthey, Shozo Kono, E. L. Bullock, and Lars Johansson
- Subjects
Double layer (biology) ,Surface (mathematics) ,Radiation ,Chemistry ,Anomalous diffraction ,Inverse photoemission spectroscopy ,Analytical chemistry ,Angle-resolved photoemission spectroscopy ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Intensity (physics) ,Adsorption ,Physical and Theoretical Chemistry ,Atomic physics ,Spectroscopy - Abstract
The angular dependence of the Si 2p photoelectron intensity has been measured for a Cs-saturated Si(001)2 x 1 surface. A surface Si 2p component, which is attributed to the Si-dimer underneath the ...
- Published
- 1998
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33. The electronic structure of the cis-bis(4,4′-dicarboxy-2,2′-bipyridine)-bis(isothiocyanato)ruthenium(II) complex and its ligand 2,2′-bipyridyl-4,4′-dicarboxylic acid studied with electron spectroscopy
- Author
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Lionel Vayssieres, Karin Westermark, Anders Hagfeldt, Paul A. Brühwiler, Hans Siegbahn, L Patthey, Sven Södergren, Håkan Rensmo, and O. Kohle
- Subjects
chemistry.chemical_classification ,Ligand ,General Physics and Astronomy ,chemistry.chemical_element ,Electronic structure ,Photochemistry ,Electron spectroscopy ,UPS ruthenium bipyridinedicarboxylate isothiocyanato complex ,2,2'-Bipyridine ,Ruthenium ,UV photoelectron ruthenium bipyridinedicarboxylate isothiocyanato complex ,chemistry.chemical_compound ,Bipyridine ,Dicarboxylic acid ,chemistry ,Polymer chemistry ,Physical and Theoretical Chemistry - Abstract
The electronic structure of cis-bis(4,4'-dicarboxy-2,2'-bipyridine)bis(isothiocyanato)ruthenium(II) and of its ligand 2,2'-bipyridine-4,4'-dicarboxylic acid was studied with electron spectroscopy. Valence level spectra were studied with respect to photoelectron angular distributions and photon energy dependence. The exptl. information coupled with semi-empirical INDO/S calcns. provides a mapping of the orbital parentage of the dye complex and its ligands. The energy levels of the dye complex in the context of a sensitized semiconductor (nanostructured TiO2) surface are related to the bands of the semiconductor.
- Published
- 1997
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34. Atomic geometry of mixed Ge-Si dimers in the initial-stage growth of Ge on Si(001)2×1
- Author
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Dilano K. Saldin, Tadashi Abukawa, E. L. Bullock, X. Chen, Shozo Kono, Lars Johansson, Junji Tani, and L. Patthey
- Subjects
Materials science ,Stage (hydrology) ,Atomic physics - Published
- 1997
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- View/download PDF
35. Design of an electron spectrometer for automated photoelectron diffractogram imaging over π steradians
- Author
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E.L. Bullock and L. Patthey
- Subjects
Photocurrent ,Diffraction ,Spectrum analyzer ,Radiation ,Electron spectrometer ,Materials science ,business.industry ,Steradian ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Auger ,Optics ,Electron optics ,Acceptance angle ,Physical and Theoretical Chemistry ,business ,Spectroscopy - Abstract
An electron spectrometer is presented which has been designed and built for the fast automated acquisition of photoelectron diffraction data over π steradians above single crystal surfaces. The principle features include the use of externally-selectable stainless steel channel arrays in front of the electron optics for high accuracy definition of the analyzer acceptance angle, a five channeltron detection system allowing the determination of the photocurrent from a given photoemission core level or Auger transition without changing the analyzer energy, a sample holder with heating and cooling capabilities which has been designed for very high (
- Published
- 1997
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36. Anisotropic breakdown of Fermi liquid quasiparticle excitations in overdoped La2−xSrxCuO4
- Author
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Joël Mesot, Stéphane Pailhès, Oscar Tjernberg, Johan Juul Chang, Thomas Claesson, L. Patthey, O. J. Lipscombe, Martin Månsson, Stephen M Hayden, Ecole Polytechnique Fédérale de Lausanne (EPFL), The Swiss Light Source (SLS) (SLS-PSI), Paul Scherrer Institute (PSI), Laboratory for Neutron Scattering and Imaging [Paul Scherrer Institute] (LNS), Royal Institute of Technology [Stockholm] (KTH ), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), H. H. Wills Physics Laboratory [Bristol], University of Bristol [Bristol], Laboratory for Solid State Physics [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), and Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)
- Subjects
High-temperature superconductivity ,General Physics and Astronomy ,02 engineering and technology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,law.invention ,[SPI]Engineering Sciences [physics] ,law ,Quantum critical point ,Condensed Matter::Superconductivity ,0103 physical sciences ,[CHIM]Chemical Sciences ,010306 general physics ,Physics ,[PHYS]Physics [physics] ,Multidisciplinary ,Condensed matter physics ,Quantum oscillations ,Fermi energy ,Fermi surface ,General Chemistry ,021001 nanoscience & nanotechnology ,Quasiparticle ,Condensed Matter::Strongly Correlated Electrons ,Fermi liquid theory ,0210 nano-technology ,Fermi gas - Abstract
International audience; High-temperature superconductivity emerges from an un-conventional metallic state. This has stimulated strong efforts to understand exactly how Fermi liquids breakdown and evolve into an un-conventional metal. A fundamental question is how Fermi liquid quasiparticle excitations break down in momentum space. Here we show, using angle-resolved photoemission spectroscopy, that the Fermi liquid quasiparticle excitations of the overdoped superconducting cuprate La1.77Sr0.23CuO4 is highly anisotropic in momentum space. The quasiparticle scattering and residue behave differently along the Fermi surface and hence the Kadowaki–Wood's relation is not obeyed. This kind of Fermi liquid breakdown may apply to a wide range of strongly correlated metal systems where spin fluctuations are present.
- Published
- 2013
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- View/download PDF
37. Spectroscopic indications of polaronic behavior of the strong spin-orbit insulator Sr3Ir2O7
- Author
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Kyle Shen, D. H. Lu, Felix Baumberger, E. Rozbicki, Robert G. Moore, L. Patthey, S. McKeown Walker, Phil D. C. King, T. Takayama, Ming Shi, H. Takagi, and Anna Tamai
- Subjects
Physics ,Condensed matter physics ,Bilayer ,Insulator (electricity) ,Strongly correlated material ,Condensed Matter Physics ,Ground state ,Electronic, Optical and Magnetic Materials - Abstract
We investigate the bilayer Ruddlesden-Popper iridate Sr${}_{3}$Ir${}_{2}$O${}_{7}$ by temperature-dependent angle-resolved photoemission. At low temperatures, we find a fully gapped correlated insulator, characterized by a small charge gap and narrow bandwidths. The low-energy spectral features show a pronounced temperature-dependent broadening and non-quasiparticle-like Gaussian line shapes. Together, these spectral features provide experimental evidence for a polaronic ground state. We observe similar behavior for the single-layer cousin Sr${}_{2}$IrO${}_{4}$, indicating that strong electron-boson coupling dominates the low-energy excitations of this exotic family of $5d$ compounds.
- Published
- 2013
- Full Text
- View/download PDF
38. Anisotropic breakdown of Fermi liquid quasiparticle excitations in overdoped La₂-xSrxCuO₄
- Author
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J, Chang, M, Månsson, S, Pailhès, T, Claesson, O J, Lipscombe, S M, Hayden, L, Patthey, O, Tjernberg, and J, Mesot
- Abstract
High-temperature superconductivity emerges from an un-conventional metallic state. This has stimulated strong efforts to understand exactly how Fermi liquids breakdown and evolve into an un-conventional metal. A fundamental question is how Fermi liquid quasiparticle excitations break down in momentum space. Here we show, using angle-resolved photoemission spectroscopy, that the Fermi liquid quasiparticle excitations of the overdoped superconducting cuprate La1.77Sr0.23CuO4 is highly anisotropic in momentum space. The quasiparticle scattering and residue behave differently along the Fermi surface and hence the Kadowaki-Wood's relation is not obeyed. This kind of Fermi liquid breakdown may apply to a wide range of strongly correlated metal systems where spin fluctuations are present.
- Published
- 2013
39. Soft-X-ray ARPES facility at the ADRESS beamline of the SLS: concepts, technical realisation and scientific applications
- Author
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Ming Shi, L. Patthey, J. Krempasky, C. Hess, X. Wang, Thorsten Schmitt, Masaki Kobayashi, and Vladimir N. Strocov
- Subjects
Physics ,Nuclear and High Energy Physics ,Radiation ,Photon ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Position and momentum space ,Angle-resolved photoemission spectroscopy ,Electronic structure ,Optical axis ,Photoexcitation ,Optics ,Beamline ,business ,Instrumentation ,Swiss Light Source - Abstract
Soft-X-ray angle-resolved photoelectron spectroscopy (ARPES) with photon energies around 1 keV combines the momentum space resolution with increasing probing depth. The concepts and technical realisation of the new soft-X-ray ARPES endstation at the ADRESS beamline of SLS are described. The experimental geometry of the endstation is characterized by grazing X-ray incidence on the sample to increase the photoyield and vertical orientation of the measurement plane. The vacuum chambers adopt a radial layout allowing most efficient sample transfer. High accuracy of the angular resolution is ensured by alignment strategies focused on precise matching of the X-ray beam and optical axis of the analyzer. The high photon flux of up to 1013 photons s−1(0.01% bandwidth)−1delivered by the beamline combined with the optimized experimental geometry break through the dramatic loss of the valence band photoexcitation cross section at soft-X-ray energies. ARPES images with energy resolution up to a few tens of meV are typically acquired on the time scale of minutes. A few application examples illustrate the power of our advanced soft-X-ray ARPES instrumentation to explore the electronic structure of bulk crystals with resolution in three-dimensional momentum, access buried heterostructures and study elemental composition of the valence states using resonant excitation.
- Published
- 2013
40. The Role of Lattice Coupling in Establishing Electronic and Magnetic Properties in Quasi-One-Dimensional Cuprates
- Author
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Jongmin Lee, T. Schmitt, Kazutaka Kudo, Ke-Jin Zhou, Zhi-Xun Shen, Thomas P. Devereaux, Brian Moritz, Yoji Koike, L. Patthey, Vladimir N. Strocov, J. van den Brink, Steven Johnston, Ming Yi, and Wei-Sheng Lee
- Subjects
Physics ,Strongly Correlated Electrons (cond-mat.str-el) ,Coupling strength ,Condensed matter physics ,Scattering ,FOS: Physical sciences ,General Physics and Astronomy ,High resolution ,Condensed Matter - Strongly Correlated Electrons ,Molecular geometry ,Lattice (order) ,Condensed Matter::Strongly Correlated Electrons ,Quasi one dimensional ,Cuprate ,Strongly correlated material - Abstract
High resolution resonant inelastic x-ray scattering has been performed to reveal the role of lattice-coupling in a family of quasi-1D insulating cuprates, Ca$_{2+5x}$Y$_{2-5x}$Cu$_5$O$_{10}$. Site-dependent low energy excitations arising from progressive emissions of a 70 meV lattice vibrational mode are resolved for the first time, providing a direct measurement of electron-lattice coupling strength. We show that such electron-lattice coupling causes doping-dependent distortions of the Cu-O-Cu bond angle, which sets the intra-chain spin exchange interactions. Our results indicate that the lattice degrees of freedom are fully integrated into the electronic behavior in low dimensional systems., 5 pages, 4 figure
- Published
- 2013
41. Angle dependence of the spin-orbit branching ratio
- Author
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Roberto Gunnella, Lars Johansson, Shozo Kono, H.W. Yeom, C. R. Natoli, E. L. Bullock, L. Patthey, and Roger Uhrberg
- Subjects
Diffraction ,Angle dependence ,Branching fraction ,Chemistry ,Surfaces and Interfaces ,Photoionization ,Photon energy ,Condensed Matter Physics ,Branching (polymer chemistry) ,Surfaces, Coatings and Films ,Azimuth ,Monolayer ,Materials Chemistry ,Atomic physics - Abstract
As 3d spin-orbit branching ratios have been measured as functions of azimuthal angle for the 1 monolayer As Si (111) -(1 × 1) and As Si (001) -(2 × 1) systems using angle resolved photoemission. At a photon energy of hv = 72 eV, the branching ratio is larger than the statistical value for both surfaces. Furthermore, strong changes in the branching ratios at this energy are observed as functions of azimuthal angle and these changes reflect the symmetries of the respective surfaces. Constant final state measurements confirm for the As Si (111) surface that the deviation from the statistical value is primarily due to the rapidly increasing As 3d photoionization cross section at this energy and show that the observed angle dependence is mostly due to photoelectron diffraction effects. At hv = 120 eV, which is at the maximum of the As 3d cross section, the branching ratio from As Si (111) is statistical and independent of angle further confirming that the nonstatistical values for this surface are due to the photoionization cross section dependence on energy. For the As Si (001) surface, however, an azimuthal angle dependence is still observed in the constant final state measurements suggesting that the nonstatistical values are due in part to some other mechanism.
- Published
- 1996
- Full Text
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42. Clean and hydroxylated rutile TiO2(110) surfaces studied by X-ray photoelectron spectroscopy
- Author
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E. L. Bullock, L. Patthey, and S.G. Steinemann
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Biocompatibility ,Chemistry ,Relaxation (NMR) ,Analytical chemistry ,Oxide ,Surfaces and Interfaces ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Core (optical fiber) ,Metal ,chemistry.chemical_compound ,X-ray photoelectron spectroscopy ,Chemical bond ,Rutile ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Physical chemistry - Abstract
The nature of the chemical bond between the native oxide of Ti metal and various adsorbing species is essential to the understanding of the biocompatibility of Ti implants. We report here photoemission measurements of the Ti2p shake-up satellite structure from clean and hydroxylated rutile TiO2(110) surfaces which show that the satellite position is a sensitive probe of surface bonding. This effect can be explained in terms of a surface specific relaxation of the photo-induced core hole. O 1s core levels are also presented and discussed in the framework of the atomic structures of these surfaces.
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- 1996
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43. Mixed Ge-Si Dimer Growth at the Ge/Si(001)-(2×1) Surface
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Lars Johansson, Tadashi Abukawa, Shozo Kono, E. L. Bullock, and L. Patthey
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Surface (mathematics) ,Materials science ,Condensed matter physics ,Dimer ,General Physics and Astronomy ,High resolution ,Electron ,Molecular physics ,law.invention ,Core (optical fiber) ,chemistry.chemical_compound ,Stranski–Krastanov growth ,chemistry ,law ,Single domain ,Scanning tunneling microscope - Abstract
The submonolayer growth of Ge on single domain Si(001)-(2 X 1) has been studied using high resolution photoemission by monitoring the Ge 3d and Si 2p core levels as functions of coverage, electron ...
- Published
- 1995
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44. Nature of Weak Magnetism inSrTiO3/LaAlO3Multilayers
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W. A. MacFarlane, D. Wang, Zaher Salman, C. D. P. Levy, M. D. Hossain, Kim H. Chow, H. Hao, M. R. Pearson, Oren Ofer, M. Ben Shalom, Thorsten Schmitt, Milan Radovic, H. Saadaoui, L. Patthey, G. M. Morris, Yoram Dagan, and R. F. Kiefl
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SIMPLE (dark matter experiment) ,Materials science ,Condensed matter physics ,Magnetism ,Superlattice ,Relaxation (NMR) ,Spin–lattice relaxation ,General Physics and Astronomy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Layer thickness ,Condensed Matter::Materials Science ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,Layer (electronics) - Abstract
We report the observation of weak magnetism in superlattices of LaAlO3/SrTiO3 using beta-detected nuclear magnetic resonance. The spin lattice relaxation rate of Li-8 in superlattices with a spacer layers of 8 and 6 unit cells of LaAlO3 exhibits a strong peak near similar to 35 K, whereas no such peak is observed in a superlattice with spacer layer thickness of 3 unit cells. We attribute the observed temperature dependence to slowing down of weakly coupled electronic moments at the LaAlO3/SrTiO3 interface. These results show that the magnetism at the interface depends strongly on the thickness of the spacer layer, and that a minimal thickness of similar to 4-6 unit cells is required for the appearance of magnetism. A simple model is used to determine that the observed relaxation is due to small fluctuating moments (similar to 0.002 mu(B)) in the two samples with a larger LaAlO3 spacer thickness. DOI: 10.1103/PhysRevLett.109.257207
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- 2012
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45. Bulk Electronic Structure of SuperconductingLaRu2P2Single Crystals Measured by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy
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Joël Mesot, Bernard Delley, Ming Shi, Zbigniew Bukowski, Vladimir N. Strocov, Nicholas C. Plumb, Milan Radovic, Johan Juul Chang, J. Karpinski, Thorsten Schmitt, L. Patthey, Michikazu Kobayashi, and Elia Razzoli
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Superconductivity ,Materials science ,Condensed matter physics ,Photoemission spectroscopy ,medicine ,General Physics and Astronomy ,Density functional theory ,Angle-resolved photoemission spectroscopy ,Electronic structure ,medicine.disease_cause ,Pnictogen ,Stoichiometry ,Ultraviolet - Abstract
We present a soft x-ray angle-resolved photoemission spectroscopy (SX-ARPES) study of the stoichiometric pnictide superconductor LaRu2P2. The observed electronic structure is in good agreement with density functional theory (DFT) calculations. However, it is significantly different from its counterpart in high-temperature superconducting Fe pnictides. In particular, the bandwidth renormalization present in the Fe pnictides (similar to 2-3) is negligible in LaRu2P2 even though the mass enhancement is similar in both systems. Our results suggest that the superconductivity in LaRu2P2 has a different origin with respect to the iron pnictides. Finally, we demonstrate that the increased probing depth of SX-ARPES, compared to the widely used ultraviolet ARPES, is essential in determining the bulk electronic structure in the experiment.
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- 2012
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46. Three-Dimensional Spin Rotations at the Fermi Surface of a Strongly Spin-Orbit Coupled Surface System
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Ralph Claessen, P. Höpfner, J. Schäfer, Bartosz Slomski, Werner Hanke, L. Patthey, Jan Hugo Dil, C. Loho, Fabian Meier, C. Blumenstein, Andrzej Fleszar, University of Zurich, and Höpfner, P
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Physics ,Strongly Correlated Electrons (cond-mat.str-el) ,Condensed matter physics ,Spin polarization ,530 Physics ,FOS: Physical sciences ,General Physics and Astronomy ,Fermi surface ,10192 Physics Institute ,02 engineering and technology ,Zero field splitting ,021001 nanoscience & nanotechnology ,01 natural sciences ,3100 General Physics and Astronomy ,3. Good health ,Condensed Matter - Strongly Correlated Electrons ,Planar ,0103 physical sciences ,Spin Hall effect ,Condensed Matter::Strongly Correlated Electrons ,Texture (crystalline) ,010306 general physics ,0210 nano-technology ,Anisotropy ,Spin-½ - Abstract
The spin texture of the metallic two-dimensional electron system (root3 x root3)-Au/Ge(111) is revealed by fully three-dimensional spin-resolved photoemission, as well as by density functional calculations. The large hexagonal Fermi surface, generated by the Au atoms, shows a significant splitting due to spin-orbit interactions. The planar components of the spin exhibit helical character, accompanied by a strong out-of-plane spin component with alternating signs along the six Fermi surface sections. Moreover, in-plane spin rotations towards a radial direction are observed close to the hexagon corners. Such a threefold-symmetric spin pattern is not described by the conventional Rashba model. Instead, it reveals an interplay with Dresselhaus-like spin-orbit effects as a result of the crystalline anisotropies., Comment: 5 pages, 4 figures, accepted at Physical Review Letters
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- 2012
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47. Bulk electronic structure of superconducting LaRu2P2 single crystals measured by soft-X-ray angle-resolved photoemission spectroscopy
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E, Razzoli, M, Kobayashi, V N, Strocov, B, Delley, Z, Bukowski, J, Karpinski, N C, Plumb, M, Radovic, J, Chang, T, Schmitt, L, Patthey, J, Mesot, and M, Shi
- Abstract
We present a soft x-ray angle-resolved photoemission spectroscopy (SX-ARPES) study of the stoichiometric pnictide superconductor LaRu(2)P(2). The observed electronic structure is in good agreement with density functional theory (DFT) calculations. However, it is significantly different from its counterpart in high-temperature superconducting Fe pnictides. In particular, the bandwidth renormalization present in the Fe pnictides (~2-3) is negligible in LaRu(2)P(2) even though the mass enhancement is similar in both systems. Our results suggest that the superconductivity in LaRu(2) P(2) has a different origin with respect to the iron pnictides. Finally, we demonstrate that the increased probing depth of SX-ARPES, compared to the widely used ultraviolet ARPES, is essential in determining the bulk electronic structure in the experiment.
- Published
- 2012
48. Nature of weak magnetism in SrTiO3/LaAlO3 multilayers
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Z, Salman, O, Ofer, M, Radovic, H, Hao, M, Ben Shalom, K H, Chow, Y, Dagan, M D, Hossain, C D P, Levy, W A, Macfarlane, G M, Morris, L, Patthey, M R, Pearson, H, Saadaoui, T, Schmitt, D, Wang, and R F, Kiefl
- Abstract
We report the observation of weak magnetism in superlattices of LaAlO(3)/SrTiO(3) using β-detected nuclear magnetic resonance. The spin lattice relaxation rate of ^{8}Li in superlattices with a spacer layers of 8 and 6 unit cells of LaAlO(3) exhibits a strong peak near ~35 K, whereas no such peak is observed in a superlattice with spacer layer thickness of 3 unit cells. We attribute the observed temperature dependence to slowing down of weakly coupled electronic moments at the LaAlO(3)/SrTiO(3) interface. These results show that the magnetism at the interface depends strongly on the thickness of the spacer layer, and that a minimal thickness of ~4-6 unit cells is required for the appearance of magnetism. A simple model is used to determine that the observed relaxation is due to small fluctuating moments (~0.002μ(B)) in the two samples with a larger LaAlO(3) spacer thickness.
- Published
- 2012
49. Emergent quantum confinement at topological insulator surfaces
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Geetha Balakrishnan, Ming Shi, L. Patthey, Ph. Hofmann, Felix Baumberger, Naoto Nagaosa, Mohammad Saeed Bahramy, Phil D. C. King, Johan Juul Chang, Ryotaro Arita, and A. de la Torre
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Surface (mathematics) ,Condensed matter ,General Physics and Astronomy ,FOS: Physical sciences ,ddc:500.2 ,02 engineering and technology ,Electronic structure ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Condensed Matter - Strongly Correlated Electrons ,0103 physical sciences ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Topological order ,010306 general physics ,Electronic band structure ,Topology (chemistry) ,Physics ,Condensed Matter - Materials Science ,Multidisciplinary ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed matter physics ,Strongly Correlated Electrons (cond-mat.str-el) ,Texture (cosmology) ,Materials Science (cond-mat.mtrl-sci) ,General Chemistry ,021001 nanoscience & nanotechnology ,Materials science ,Physical sciences ,Band bending ,Topological insulator ,0210 nano-technology - Abstract
Bismuth-chalchogenides are model examples of three-dimensional topological insulators. Their ideal bulk-truncated surface hosts a single spin-helical surface state, which is the simplest possible surface electronic structure allowed by their non-trivial $\mathbb{Z}_2$ topology. They are therefore widely regarded ideal templates to realize the predicted exotic phenomena and applications of this topological surface state. However, real surfaces of such compounds, even if kept in ultra-high vacuum, rapidly develop a much more complex electronic structure whose origin and properties have proved controversial. Here, we demonstrate that a conceptually simple model, implementing a semiconductor-like band bending in a parameter-free tight-binding supercell calculation, can quantitatively explain the entire measured hierarchy of electronic states. In combination with circular dichroism in angle-resolved photoemission (ARPES) experiments, we further uncover a rich three-dimensional spin texture of this surface electronic system, resulting from the non-trivial topology of the bulk band structure. Moreover, our study reveals how the full surface-bulk connectivity in topological insulators is modified by quantum confinement., Comment: 9 pages, including supplementary information, 4+4 figures. A high resolution version is available at http://www.st-andrews.ac.uk/~pdk6/pub_files/TI_quant_conf_high_res.pdf
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- 2012
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50. Electronic band structure of the two-dimensional metallic electron system Au/Ge(111)
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C. Blumenstein, Ralph Claessen, P. Höpfner, T. Schramm, Werner Hanke, S. Meyer, Xiaoyu Cui, M. Heßmann, Andrzej Fleszar, J. Schäfer, and L. Patthey
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Physics ,Condensed matter physics ,Fermi surface ,Electronic structure ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Metal ,Character (mathematics) ,Atomic orbital ,visual_art ,visual_art.visual_art_medium ,Density functional theory ,Electronic band structure ,Charge density wave - Abstract
The two-dimensional electron system Au/Ge(111)-($\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}$)$R$30\ifmmode^\circ\else\textdegree\fi{} is studied in detail by angle-resolved photoemission and density functional theory calculations. In combining these results, we identify four metallic bands which are either of dominantly Au or Ge character, respectively. The largest Fermi surface sheet, originating from Au orbitals, is suggestive of a nesting condition due to its hexagonal shape. However, a charge density wave transition is not observed between room temperature and 10 K. The electronic structure obtained by density functional theory with inclusion of a self-energy correction is in good agreement with the experiment. These calculations also indicate that there is significant spin-orbit splitting, especially in the Au-related bands, which is partly of Rashba character.
- Published
- 2011
- Full Text
- View/download PDF
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