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1. Improving the Electro-Optical Properties of MoS$_2$/rGO Hybrid Nanocomposites Using Liquid Crystals

Author

Vasilev, A., Melikyan, Y., Zhezhu, M., Hayrapetyan, V., Torosyan, M. S., Ghazaryan, D. A., Yeranosyan, M., and Gharagulyan, H.

Subjects
Condensed Matter - Materials Science, Physics - Applied Physics, 14J60 (Primary) 14F05, 14J26 (Secondary), F.2.2, I.2.7
Abstract

Hybrid systems of two-dimensional (2D) materials (such as graphene-family materials and 2D transition metal dichalcogenides) are attracting much attention due to their distinctive optoelectronic, thermal, mechanical, and chemical properties. The application perspectives of these materials in various fields further expand when enriching those with liquid crystals (LCs) primarily due to their enhanced tunability and functionality. In this study, we report on the hydrothermal synthesis of hybrid nanocomposites composed of MoS$_2$ and rGO and discuss tuning possibilities of their electro-optical properties by incorporating thermotropic LCs. In particular, we demonstrate that the incorporation of 5CB LC increases the sensitivity and charge storage efficiency of the hybrid nanocomposites. In addition, we also present the responsivity, detectivity, and response time properties of the hybrid nanocomposites of MoS$_2$/rGO, both with and without the inclusion of nematic LCs. Furthermore, we demonstrate that the system exhibits a 5CB-induced photocurrent switching effect. We believe the findings will open new doors for applications of these materials in optoelectronics and photonics., Comment: 3 figures, 113036 page, research paper

Published
2024
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2. Nanopatterning of multicomponent van der Waals heterostructures using atomic force microscopy

Author

Shilov, A. L., Elesin, L., Grebenko, A., Kleshch, V. I., Kashchenko, M. A., Mazurenko, I., Titova, E., Zharkova, E., Yakovlev, D. S., Novoselov, K. S., Ghazaryan, D. A., Dremov, V., and Bandurin, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
Abstract

Multilayer van der Waals (vdW) heterostructures have become an important platform in which to study novel fundamental effects emerging at the nanoscale. Standard nanopatterning techniques relying on electron-beam lithography and reactive ion etching, widely applied to pattern such heterostructures, however, impose some limitations on the edge accuracy and resolution, as revealed through numerous experiments with vdW quantum dots and point contacts. Here we present an alternative approach for electrode-free nanopatterning of thick multilayer vdW heterostructures based on atomic force microscopy (AFM). By applying an AC voltage of a relatively small frequency (1-10 kHz) between the sharp platinum tip and the substrate, we realize high-resolution ($\lesssim 100$ nm) etching of thick multicomponent heterostructures if the latter are deposited onto graphite slabs. Importantly, unlike more conventional electrode-free local anodic oxidation, our method does not require a special environment with excess humidity, can be applied at ambient conditions, and enables the patterning of multilayer heterostructures composed of graphene, graphite, hexagonal boron nitride (hBN), NbSe$_{2}$, WSe$_{2}$, and more., Comment: 6 pages; 3 figures

Published
2024

3. E-Beam Induced Micropattern Generation and Amorphization of L-Cysteine-Functionalized Graphene Oxide Nano-composites

Author

Melikyan, Y., Gharagulyan, H., Vasilev, A., Hayrapetyan, V., Zhezhu, M., Simonyan, A., Ghazaryan, D. A., Torosyan, M. S., Kharatyan, A., Michalicka, J., and Yeranosyan, M.

Subjects
Condensed Matter - Materials Science, Physics - Applied Physics
Abstract

The evolution of dynamic processes in graphene-family materials are of great interest for both scientific purposes and technical applications. Scanning electron microscopy and transmission electron microscopy outstand among the techniques that allow both observing and controlling such dynamic processes in real time. On the other hand, functionalized graphene oxide emerges as a favorable candidate from graphene-family materials for such an investigation due to its distinctive properties, that encompass a large surface area, robust thermal stability, and noteworthy electrical and mechanical properties after its reduction. Here, we report on studies of surface structure and adsorption dynamics of L-Cysteine on electrochemically exfoliated graphene oxides basal plane. We show that electron beam irradiation prompts an amorphization of functionalized graphene oxide along with the formation of micropatterns of controlled geometry composed of L-Cysteine-Graphene oxide nanostructures. The controlled growth and predetermined arrangement of micropatterns as well as controlled structure disorder induced by e beam amorphization, in its turn potentially offering tailored properties and functionalities paving the way for potential applications in nanotechnology, sensor development, and surface engineering. Our findings demonstrate that graphene oxide can cover L-Cysteine in such a way to provide a control on the positioning of emerging microstructures about 10-20 um in diameter. Besides, Raman and SAED measurement analyses yield above 50% amorphization in a material. The results of our studies demonstrate that such a technique enables the direct creation of micropatterns of L-Cysteine-Graphene oxide eliminating the need for complicated mask patterning procedures.

Published
2024
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4. Essential L-Amino Acid-Functionalized Graphene Oxide for Liquid Crystalline Phase Formation

Author

Gharagulyan, H., Melikyan, Y., Hayrapetyan, V., Kirakosyan, Kh., Ghazaryan, D. A., and Yeranosyan, M.

Subjects
Condensed Matter - Materials Science
Abstract

The colloidal 2D materials based on graphene and its modifications are of great interest when it comes to forming LC phases. These LC phases allow controlling the orientational order of colloidal particles, paving the way for the efficient processing of modified graphene with anisotropic properties. Here, we present the peculiarities of AA functionalization of GO, along with the formation of its LC phase and orientational behavior in an external magnetic field. We discuss the influence of pH on the GOLC, ultimately showing its pH-dependent behavior for GO-AA complexes. In addition, we observe different GO morphology changes due to the presence of AA functional groups, namely L-cysteine dimerization on the GO platform. The pH dependency of AA-functionalized LC phase of GO is examined for the first time. We believe that our studies will open new possibilities for applications in bionanotechnologies due to self-assembling properties of LCs and magnificent properties of GO., Comment: 10 pages, 16 figures

Published
2023
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5. Hexagonal boron nitride nanophotonics

Author

Grudinin, D. V., Ermolaev, G. A., Baranov, D. G., Toksumakov, A. N., Voronin, K. V., Slavich, A. S., Vyshnevyy, A. A., Mazitov, A. B., Kruglov, I. A., Ghazaryan, D., Arsenin, A. V., Novoselov, K. S., and Volkov, V. S.

Subjects
Physics - Optics, Condensed Matter - Materials Science, Physics - Applied Physics
Abstract

A global trend to miniaturization and multiwavelength performance of nanophotonic devices drives research on novel phenomena, such as bound states in the continuum and Mietronics, as well as the survey for high-refractive index and strongly anisotropic materials and metasurfaces. Hexagonal boron nitride (hBN) is one of promising materials for the future nanophotonics owing to its inherent anisotropy and prospects of high-quality monocrystals growth with atomically flat surface. Here, we present highly accurate optical constants of hBN in the broad wavelength range of 250-1700 nm combining the imaging ellipsometry measurements scanning near-field optical microscopy and first-principle quantum mechanical computations. hBN's high refractive index, up to 2.75 in ultraviolet (UV) and visible range, broadband birefringence of 0.7, and negligible optical losses make it an outstanding material for UV and visible range photonics. Based on our measurement results, we propose and design novel optical elements: handedness-preserving mirrors and subwavelength waveguides with dimensions of 40 nm operating in the visible and UV range, respectively. Remarkably, our results offer unique opportunity to bridge the size-gap between photonics and electronics., Comment: 12 pages, 4 figures

Published
2023

6. Field-induced insulating states in a graphene superlattice

Author

Pezzini, S., Wiedmann, S., Mishchenko, A., Holwill, M., Gorbachev, R., Ghazaryan, D., Novoselov, K. S., and Zeitler, U.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We report on high-field magnetotransport (B up to 35 T) on a gated superlattice based on single-layer graphene aligned on top of hexagonal boron nitride. The large-period moir\'e modulation (15 nm) enables us to access the Hofstadter spectrum in the vicinity of and above one flux quantum per superlattice unit cell (Phi/Phi_0 = 1 at B = 22 T). We thereby reveal, in addition to the spin-valley antiferromagnet at nu = 0, two insulating states developing in positive and negative effective magnetic fields from the main nu = 1 and nu = -2 quantum Hall states respectively. We investigate the field dependence of the energy gaps associated with these insulating states, which we quantify from the temperature-activated peak resistance. Referring to a simple model of local Landau quantization of third generation Dirac fermions arising at Phi/Phi_0 = 1, we describe the different microscopic origins of the insulating states and experimentally determine the energy-momentum dispersion of the emergent gapped Dirac quasi-particles.

Published
2019
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7. Tunnel spectroscopy of localised electronic states in hexagonal boron nitride

Author

Greenaway, M. T., Vdovin, E. E., Ghazaryan, D., Misra, A., Mishchenko, A., Cao, Y., Wang, Z., Wallbank, J. R., Holwill, M., Khanin, Yu. N., Morozov, S. V., Watanabe, K., Taniguchi, T., Makarovsky, O., Fromhold, T. M., Patanè, A., Geim, A. K., Fal'ko, V. I., Novoselov, K. S., and Eaves, L.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Hexagonal boron nitride (hBN) is a large band gap layered crystal, frequently incorporated in van der Waals (vdW) heterostructures as an insulating or tunnel barrier. Localised states with energies within its band gap can emit visible light, relevant to applications in nanophotonics and quantum information processing. However, they also give rise to conducting channels, which can induce electrical breakdown when a large voltage is applied. Here we use gated tunnel transistors to study resonant electron tunnelling through the localised states in few atomic-layer hBN barriers sandwiched between two monolayer graphene electrodes. The measurements are used to determine the energy, linewidth, tunnelling transmission probability, and depth within the barrier of more than 50 distinct localised states. A three-step process of electron percolation through two spatially separated localised states is also investigated., Comment: Supplementary information can be found at https://doi.org/10.1038/s42005-018-0097-1

Published
2018
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8. Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures

Author

Wallbank, J. R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J. S., Piot, B. A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T. L. M., Morozov, S. V., Greenaway, M. T., Eaves, L., Geim, A. K., Fal'ko, V. I., Novoselov, K. S., and Mishchenko, A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here we report the direct observation and manipulation of chirality and pseudospin polarization in the tunneling of electrons between two almost perfectly aligned graphene crystals. We use a strong in-plane magnetic field as a tool to resolve the contributions of the chiral electronic states that have a phase difference between the two components of their vector wavefunction. Our experiments not only shed light on chirality, but also demonstrate a technique for preparing graphene's Dirac electrons in a particular quantum chiral state in a selected valley., Comment: 26 pages, 13 figures

Published
2016
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9. Phonon-assisted resonant tunneling of electrons in graphene-boron nitride transistors

Author

Vdovin, E. E., Mishchenko, A., Greenaway, M. T., Zhu, M. J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S. V., Makarovsky, O., Patanè, A., Slotman, G. J., Katsnelson, M. I., Geim, A. K., Novoselov, K. S., and Eaves, L.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between $\sim$10 and 200 mV. We attribute them to electron tunneling assisted by the emission of phonons of well-defined energy. The bias voltages at which they occur are insensitive to the applied gate voltage and hence independent of the carrier densities in the graphene electrodes, so plasmonic effects can be ruled out. The phonon energies corresponding to the resonances are compared with the lattice dispersion curves of graphene-boron nitride heterostructures and are close to peaks in the single phonon density of states.

Published
2015
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11. Polarization control of lasing from few-layer MoTe2 coupled with the optical metasurface supporting quasi-trapped modes.

Author

Prokhorov, A. V., Toksumakov, A. N., Shesterikov, A. V., Maksimov, F. M., Tatmyshevskiy, M. K., Gubin, M. Yu., Kirtaev, R. V., Titova, E. I., Yakubovsky, D. I., Zhukova, E. S., Burdin, V. V., Novikov, S. M., Chernov, A. I., Ghazaryan, D. A., Arsenin, A. V., and Volkov, V. S.

Subjects
SURFACE emitting lasers, ELECTROMAGNETIC waves, TRANSITION metals, LASERS
Abstract

The development of technology for integrating optical metaresonators with two-dimensional and layered van der Waals (vdW) materials opens up broad prospects for the creation of subdiffraction concentrators of electromagnetic energy, surface-emitting lasers, laser displays, and highly efficient nonlinear converters. In this work, we develop a straightforward strategy for the design and fabrication of surface-emitting laser devices based on few-layer transition metal dichalcogenides placed on the dielectric metasurfaces in the regime of quasi-trapped mode excitation. We optimize the parameters of MoTe2 flake and Si metasurface to achieve a positive feedback and to observe the lasing, resulting from their integration, with the predicted characteristics. Promising potential for the development of vdW-metalaser platform is associated with the possibility of simple polarization control of lasing regimes by employing the features of the bianisotropic response of the metasurface's building blocks. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Dry Assembly of van der Waals Heterostructures Using Exfoliated and CVD-Grown 2D Materials.

Author

Adilet N. Toksumakov, Sidorova, M. N., Slavich, A. S., Tatmyshevskiy, M. K., Zavidovskiy, I. A., Ermolaev, G. A., Volkov, V. S., Ghazaryan, D. A., and Arsenin, A. V.

Abstract

Van der Waals (vdW) heterostructures are stacks of two-dimensional (2D) materials that can exhibit novel physical phenomena and open a door to new device applications. A common method to create such heterostructures is the dry transfer of mechanically cleaved 2D layers, which are usually small in size and limited in material diversity. Here, we propose a simple and clean dry assembly method using polydimethylsiloxane (PDMS) to construct heterostructures based on both mechanically exfoliated and chemically vapor deposited (CVD) 2D materials. This technique allows us to combine the advantages of both types of materials, such as large size, high quality, and a wide range of properties. We demonstrate the feasibility and versatility of our method by fabricating various heterostructures with different combinations of CVD and exfoliated 2D materials, such as graphene, hexagonal boron nitride, molybdenum disulfide, and tungsten diselenide. Our method opens new possibilities for exploring the physics and applications of van der Waals heterostructures. [ABSTRACT FROM AUTHOR]

Published
2023
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14. Hexagonal boron nitride nanophotonics: a record-breaking material for the ultraviolet and visible spectral ranges

Author

Grudinin, D. V., primary, Ermolaev, G. A., additional, Baranov, D. G., additional, Toksumakov, A. N., additional, Voronin, K. V., additional, Slavich, A. S., additional, Vyshnevyy, A. A., additional, Mazitov, A. B., additional, Kruglov, I. A., additional, Ghazaryan, D. A., additional, Arsenin, A. V., additional, Novoselov, K. S., additional, and Volkov, V. S., additional

Published
2023
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18. Tunnel spectroscopy of localised electronic states in hexagonal boron nitride

Author

Greenaway, M. T., primary, Vdovin, E. E., additional, Ghazaryan, D., additional, Misra, A., additional, Mishchenko, A., additional, Cao, Y., additional, Wang, Z., additional, Wallbank, J. R., additional, Holwill, M., additional, Khanin, Yu.N., additional, Morozov, S. V., additional, Watanabe, K., additional, Taniguchi, T., additional, Makarovsky, O., additional, Fromhold, T. M., additional, Patanè, A., additional, Geim, A. K., additional, Fal’ko, V. I., additional, Novoselov, K. S., additional, and Eaves, L., additional

Published
2018
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19. Unusual Suppression of the Superconducting Energy Gap and Critical Temperature in Atomically Thin NbSe2

Author

Khestanova, E., primary, Birkbeck, J., additional, Zhu, M., additional, Cao, Y., additional, Yu, G. L., additional, Ghazaryan, D., additional, Yin, J., additional, Berger, H., additional, Forró, L., additional, Taniguchi, T., additional, Watanabe, K., additional, Gorbachev, R. V., additional, Mishchenko, A., additional, Geim, A. K., additional, and Grigorieva, I. V., additional

Published
2018
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20. Phonon-assisted resonant tunneling of electrons in graphene–boron nitride transistors

Author

Vdovin, E. E., Mishchenko, A., Greenaway, M. T., Zhu, M. J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S. V., Makarovsky, O., Fromhold, T. M., Patanè, A., Slotman, G. J., Katsnelson, M. I., Geim, A. K., Novoselov, K. S., and Eaves, L.

Subjects
Condensed Matter::Materials Science, Condensed Matter::Superconductivity, Physics::Atomic and Molecular Clusters, Physics::Optics, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
Abstract

We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between 10 and 200 mV. We attribute them to electron tunneling assisted by the emission of phonons of well-defined energy. The bias voltages at which they occur are insensitive to the applied gate voltage and hence independent of the carrier densities in the graphene electrodes, so plasmonic effects can be ruled out. The phonon energies corresponding to the resonances are compared with the lattice dispersion curves of graphene–boron nitride heterostructures and are close to peaks in the single phonon density of states.

Published
2016

21. Phonon-Assisted Resonant Tunneling of Electrons in Graphene–Boron Nitride Transistors

Author

Vdovin, Evgeny E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, Oleg, Fromhold, T.M., Slotman, G.J., Katsnelson, M. I, Geim, A.K., Nososelov, K.S., and Eaves, Laurence

Subjects
Condensed Matter::Materials Science, Condensed Matter::Superconductivity, Physics::Atomic and Molecular Clusters, Physics::Optics, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
Abstract

We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between 10 and 200 mV. We attribute them to electron tunneling assisted by the emission of phonons of well-defined energy. The bias voltages at which they occur are insensitive to the applied gate voltage and hence independent of the carrier densities in the graphene electrodes, so plasmonic effects can be ruled out. The phonon energies corresponding to the resonances are compared with the lattice dispersion curves of graphene-boron nitride heterostructures and are close to peaks in the single phonon density of states.

Published
2016

22. Phonon-Assisted Resonant Tunneling of Electrons in Graphene-Boron Nitride Transistors

Author

Vdovin, E.E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, O., Fromhold, T.M., Patane, A., Slotman, G.J., Katsnelson, M.I., Geim, A.K., Novoselov, K.S., Eaves, L., Vdovin, E.E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, O., Fromhold, T.M., Patane, A., Slotman, G.J., Katsnelson, M.I., Geim, A.K., Novoselov, K.S., and Eaves, L.

Abstract

Contains fulltext : 158674.pdf (preprint version ) (Open Access)

Published
2016

23. Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures

Author

Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S.R., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, L., Geim, A.K., Fal'ko, V.I., Novoselov, K.S., Mishchenko, A., Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S.R., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, L., Geim, A.K., Fal'ko, V.I., Novoselov, K.S., and Mishchenko, A.

Abstract

Contains fulltext : 159887.pdf (preprint version ) (Closed access)

Published
2016

24. Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures

Author

Wallbank, J. R., primary, Ghazaryan, D., additional, Misra, A., additional, Cao, Y., additional, Tu, J. S., additional, Piot, B. A., additional, Potemski, M., additional, Pezzini, S., additional, Wiedmann, S., additional, Zeitler, U., additional, Lane, T. L. M., additional, Morozov, S. V., additional, Greenaway, M. T., additional, Eaves, L., additional, Geim, A. K., additional, Fal'ko, V. I., additional, Novoselov, K. S., additional, and Mishchenko, A., additional

Published
2016
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29. Magnon-assisted tunnelling in van der Waals heterostructures based on CrBr3

Author

Ghazaryan, D., Greenaway, M.T., Wang, Z., Guarochico-Moreira, V.H., Vera-Marun, I.J., Yin, J., Liao, Y., Morozov, S.V., Kristanovski, O., Lichtenstein, A.I., Katsnelson, M.I., Withers, F., Mishchenko, A., Eaves, Laurence, Geim, A.K., Novoselov, K.S., Misra, A., Ghazaryan, D., Greenaway, M.T., Wang, Z., Guarochico-Moreira, V.H., Vera-Marun, I.J., Yin, J., Liao, Y., Morozov, S.V., Kristanovski, O., Lichtenstein, A.I., Katsnelson, M.I., Withers, F., Mishchenko, A., Eaves, Laurence, Geim, A.K., Novoselov, K.S., and Misra, A.

Abstract

Van der Waals heterostructures, which are composed of layered two-dimensional materials, offer a platform to investigate a diverse range of physical phenomena and could be of use in a variety of applications. Heterostructures containing two-dimensional ferromagnets, such as chromium triiodide (CrI3), have recently been reported, which could allow two-dimensional spintronic devices to be developed. Here we study tunnelling through thin ferromagnetic chromium tribromide (CrBr3) barriers that are sandwiched between graphene electrodes. In devices with non-magnetic barriers, conservation of momentum can be relaxed by phonon-assisted tunnelling or by tunnelling through localized states. In contrast, in the devices with ferromagnetic barriers, the major tunnelling mechanisms are the emission of magnons at low temperatures and the scattering of electrons on localized magnetic excitations at temperatures above the Curie temperature. Magnetoresistance in the graphene electrodes further suggests induced spin–orbit coupling and proximity exchange via the ferromagnetic barrier. Tunnelling with magnon emission offers the possibility of spin injection.

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30. Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures

Author

Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S., Mishchenko, A., Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S., and Mishchenko, A.

Abstract

Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here we report the direct observation and manipulation of chirality and pseudospin polarization in the tunneling of electrons between two almost perfectly aligned graphene crystals. We use a strong in-plane magnetic field as a tool to resolve the contributions of the chiral electronic states that have a phase difference between the two components of their vector wavefunction. Our experiments not only shed light on chirality, but also demonstrate a technique for preparing graphene’s Dirac electrons in a particular quantum chiral state in a selected valley.

Full Text
View/download PDF

31. Phonon-assisted resonant tunneling of electrons in graphene–boron nitride transistors

Author

Vdovin, Evgeny E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, Oleg, Fromhold, T.M., Patanè, Amalia, Slotman, G.J., Katsnelson, M.I., Geim, A K., Novoselov, K.S., Eaves, Laurence, Vdovin, Evgeny E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, Oleg, Fromhold, T.M., Patanè, Amalia, Slotman, G.J., Katsnelson, M.I., Geim, A K., Novoselov, K.S., and Eaves, Laurence

Abstract

We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between 10 and 200 mV. We attribute them to electron tunneling assisted by the emission of phonons of well-defined energy. The bias voltages at which they occur are insensitive to the applied gate voltage and hence independent of the carrier densities in the graphene electrodes, so plasmonic effects can be ruled out. The phonon energies corresponding to the resonances are compared with the lattice dispersion curves of graphene–boron nitride heterostructures and are close to peaks in the single phonon density of states.

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32. Magnon-assisted tunnelling in van der Waals heterostructures based on CrBr3

Author

Ghazaryan, D., Greenaway, M.T., Wang, Z., Guarochico-Moreira, V.H., Vera-Marun, I.J., Yin, J., Liao, Y., Morozov, S.V., Kristanovski, O., Lichtenstein, A.I., Katsnelson, M.I., Withers, F., Mishchenko, A., Eaves, Laurence, Geim, A.K., Novoselov, K.S., Misra, A., Ghazaryan, D., Greenaway, M.T., Wang, Z., Guarochico-Moreira, V.H., Vera-Marun, I.J., Yin, J., Liao, Y., Morozov, S.V., Kristanovski, O., Lichtenstein, A.I., Katsnelson, M.I., Withers, F., Mishchenko, A., Eaves, Laurence, Geim, A.K., Novoselov, K.S., and Misra, A.

Abstract

Van der Waals heterostructures, which are composed of layered two-dimensional materials, offer a platform to investigate a diverse range of physical phenomena and could be of use in a variety of applications. Heterostructures containing two-dimensional ferromagnets, such as chromium triiodide (CrI3), have recently been reported, which could allow two-dimensional spintronic devices to be developed. Here we study tunnelling through thin ferromagnetic chromium tribromide (CrBr3) barriers that are sandwiched between graphene electrodes. In devices with non-magnetic barriers, conservation of momentum can be relaxed by phonon-assisted tunnelling or by tunnelling through localized states. In contrast, in the devices with ferromagnetic barriers, the major tunnelling mechanisms are the emission of magnons at low temperatures and the scattering of electrons on localized magnetic excitations at temperatures above the Curie temperature. Magnetoresistance in the graphene electrodes further suggests induced spin–orbit coupling and proximity exchange via the ferromagnetic barrier. Tunnelling with magnon emission offers the possibility of spin injection.

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33. Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures

Author

Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S., Mishchenko, A., Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S., and Mishchenko, A.

Abstract

Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here we report the direct observation and manipulation of chirality and pseudospin polarization in the tunneling of electrons between two almost perfectly aligned graphene crystals. We use a strong in-plane magnetic field as a tool to resolve the contributions of the chiral electronic states that have a phase difference between the two components of their vector wavefunction. Our experiments not only shed light on chirality, but also demonstrate a technique for preparing graphene’s Dirac electrons in a particular quantum chiral state in a selected valley.

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34. Phonon-assisted resonant tunneling of electrons in graphene–boron nitride transistors

Author

Vdovin, Evgeny E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, Oleg, Fromhold, T.M., Patanè, Amalia, Slotman, G.J., Katsnelson, M.I., Geim, A K., Novoselov, K.S., Eaves, Laurence, Vdovin, Evgeny E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, Oleg, Fromhold, T.M., Patanè, Amalia, Slotman, G.J., Katsnelson, M.I., Geim, A K., Novoselov, K.S., and Eaves, Laurence

Abstract

We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between 10 and 200 mV. We attribute them to electron tunneling assisted by the emission of phonons of well-defined energy. The bias voltages at which they occur are insensitive to the applied gate voltage and hence independent of the carrier densities in the graphene electrodes, so plasmonic effects can be ruled out. The phonon energies corresponding to the resonances are compared with the lattice dispersion curves of graphene–boron nitride heterostructures and are close to peaks in the single phonon density of states.

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35. Magnon-assisted tunnelling in van der Waals heterostructures based on CrBr3

Author

Ghazaryan, D., Greenaway, M.T., Wang, Z., Guarochico-Moreira, V.H., Vera-Marun, I.J., Yin, J., Liao, Y., Morozov, S.V., Kristanovski, O., Lichtenstein, A.I., Katsnelson, M.I., Withers, F., Mishchenko, A., Eaves, Laurence, Geim, A.K., Novoselov, K.S., Misra, A., Ghazaryan, D., Greenaway, M.T., Wang, Z., Guarochico-Moreira, V.H., Vera-Marun, I.J., Yin, J., Liao, Y., Morozov, S.V., Kristanovski, O., Lichtenstein, A.I., Katsnelson, M.I., Withers, F., Mishchenko, A., Eaves, Laurence, Geim, A.K., Novoselov, K.S., and Misra, A.

Abstract

Van der Waals heterostructures, which are composed of layered two-dimensional materials, offer a platform to investigate a diverse range of physical phenomena and could be of use in a variety of applications. Heterostructures containing two-dimensional ferromagnets, such as chromium triiodide (CrI3), have recently been reported, which could allow two-dimensional spintronic devices to be developed. Here we study tunnelling through thin ferromagnetic chromium tribromide (CrBr3) barriers that are sandwiched between graphene electrodes. In devices with non-magnetic barriers, conservation of momentum can be relaxed by phonon-assisted tunnelling or by tunnelling through localized states. In contrast, in the devices with ferromagnetic barriers, the major tunnelling mechanisms are the emission of magnons at low temperatures and the scattering of electrons on localized magnetic excitations at temperatures above the Curie temperature. Magnetoresistance in the graphene electrodes further suggests induced spin–orbit coupling and proximity exchange via the ferromagnetic barrier. Tunnelling with magnon emission offers the possibility of spin injection.

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36. Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures

Author

Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S., Mishchenko, A., Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S., and Mishchenko, A.

Abstract

Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here we report the direct observation and manipulation of chirality and pseudospin polarization in the tunneling of electrons between two almost perfectly aligned graphene crystals. We use a strong in-plane magnetic field as a tool to resolve the contributions of the chiral electronic states that have a phase difference between the two components of their vector wavefunction. Our experiments not only shed light on chirality, but also demonstrate a technique for preparing graphene’s Dirac electrons in a particular quantum chiral state in a selected valley.

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37. Magnon-assisted tunnelling in van der Waals heterostructures based on CrBr3

Author

Ghazaryan, D., Greenaway, M.T., Wang, Z., Guarochico-Moreira, V.H., Vera-Marun, I.J., Yin, J., Liao, Y., Morozov, S.V., Kristanovski, O., Lichtenstein, A.I., Katsnelson, M.I., Withers, F., Mishchenko, A., Eaves, Laurence, Geim, A.K., Novoselov, K.S., Misra, A., Ghazaryan, D., Greenaway, M.T., Wang, Z., Guarochico-Moreira, V.H., Vera-Marun, I.J., Yin, J., Liao, Y., Morozov, S.V., Kristanovski, O., Lichtenstein, A.I., Katsnelson, M.I., Withers, F., Mishchenko, A., Eaves, Laurence, Geim, A.K., Novoselov, K.S., and Misra, A.

Abstract

Van der Waals heterostructures, which are composed of layered two-dimensional materials, offer a platform to investigate a diverse range of physical phenomena and could be of use in a variety of applications. Heterostructures containing two-dimensional ferromagnets, such as chromium triiodide (CrI3), have recently been reported, which could allow two-dimensional spintronic devices to be developed. Here we study tunnelling through thin ferromagnetic chromium tribromide (CrBr3) barriers that are sandwiched between graphene electrodes. In devices with non-magnetic barriers, conservation of momentum can be relaxed by phonon-assisted tunnelling or by tunnelling through localized states. In contrast, in the devices with ferromagnetic barriers, the major tunnelling mechanisms are the emission of magnons at low temperatures and the scattering of electrons on localized magnetic excitations at temperatures above the Curie temperature. Magnetoresistance in the graphene electrodes further suggests induced spin–orbit coupling and proximity exchange via the ferromagnetic barrier. Tunnelling with magnon emission offers the possibility of spin injection.

Full Text
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38. Phonon-assisted resonant tunneling of electrons in graphene–boron nitride transistors

Author

Vdovin, Evgeny E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, Oleg, Fromhold, T.M., Patanè, Amalia, Slotman, G.J., Katsnelson, M.I., Geim, A K., Novoselov, K.S., Eaves, Laurence, Vdovin, Evgeny E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, Oleg, Fromhold, T.M., Patanè, Amalia, Slotman, G.J., Katsnelson, M.I., Geim, A K., Novoselov, K.S., and Eaves, Laurence

Abstract

We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between 10 and 200 mV. We attribute them to electron tunneling assisted by the emission of phonons of well-defined energy. The bias voltages at which they occur are insensitive to the applied gate voltage and hence independent of the carrier densities in the graphene electrodes, so plasmonic effects can be ruled out. The phonon energies corresponding to the resonances are compared with the lattice dispersion curves of graphene–boron nitride heterostructures and are close to peaks in the single phonon density of states.

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39. Tuning the valley and chiral quantum state of Dirac electrons in van der Waals heterostructures

Author

Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S., Mishchenko, A., Wallbank, J.R., Ghazaryan, D., Misra, A., Cao, Y., Tu, J.S., Piot, B.A., Potemski, M., Pezzini, S., Wiedmann, S., Zeitler, U., Lane, T.L.M., Morozov, S.V., Greenaway, M.T., Eaves, Laurence, Geim, A.K., Fal'ko, V.I., Novoselov, K.S., and Mishchenko, A.

Abstract

Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here we report the direct observation and manipulation of chirality and pseudospin polarization in the tunneling of electrons between two almost perfectly aligned graphene crystals. We use a strong in-plane magnetic field as a tool to resolve the contributions of the chiral electronic states that have a phase difference between the two components of their vector wavefunction. Our experiments not only shed light on chirality, but also demonstrate a technique for preparing graphene’s Dirac electrons in a particular quantum chiral state in a selected valley.

Full Text
View/download PDF

40. Phonon-assisted resonant tunneling of electrons in graphene–boron nitride transistors

Author

Vdovin, Evgeny E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, Oleg, Fromhold, T.M., Patanè, Amalia, Slotman, G.J., Katsnelson, M.I., Geim, A K., Novoselov, K.S., Eaves, Laurence, Vdovin, Evgeny E., Mishchenko, A., Greenaway, M.T., Zhu, M.J., Ghazaryan, D., Misra, A., Cao, Y., Morozov, S.V., Makarovsky, Oleg, Fromhold, T.M., Patanè, Amalia, Slotman, G.J., Katsnelson, M.I., Geim, A K., Novoselov, K.S., and Eaves, Laurence

Abstract

We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between 10 and 200 mV. We attribute them to electron tunneling assisted by the emission of phonons of well-defined energy. The bias voltages at which they occur are insensitive to the applied gate voltage and hence independent of the carrier densities in the graphene electrodes, so plasmonic effects can be ruled out. The phonon energies corresponding to the resonances are compared with the lattice dispersion curves of graphene–boron nitride heterostructures and are close to peaks in the single phonon density of states.

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41. Unusual Suppression of the Superconducting Energy Gap and Critical Temperature in Atomically Thin NbSe2.

Author

Khestanova, E., Birkbeck, J., Zhu, M., Cao, Y., Yu, G. L., Ghazaryan, D., Yin, J., Berger, H., Forró, L., Taniguchi, T., Watanabe, K., Gorbachev, R. V., Mishchenko, A., Geim, A. K., and Grigorieva, I. V.

Subjects
*BAND gaps, *THIN films, *COULOMB potential, *SUPERCONDUCTORS, *ELECTRONIC band structure
Abstract

It is well-known that superconductivity in thin films is generally suppressed with decreasing thickness. This suppression is normally governed by either disorder-induced localization of Cooper pairs, weakening of Coulomb screening, or generation and unbinding of vortex–antivortex pairs as described by the Berezinskii–Kosterlitz–Thouless (BKT) theory. Defying general expectations, few-layer NbSe2, an archetypal example of ultrathin superconductors, has been found to remain superconducting down to monolayer thickness. Here, we report measurements of both the superconducting energy gap Δ and critical temperature TC in high-quality monocrystals of few-layer NbSe2, using planar-junction tunneling spectroscopy and lateral transport. We observe a fully developed gap that rapidly reduces for devices with the number of layers N ≤ 5, as does their TC. We show that the observed reduction cannot be explained by disorder, and the BKT mechanism is also excluded by measuring its transition temperature that for all N remains very close to TC. We attribute the observed behavior to changes in the electronic band structure predicted for mono- and bi- layer NbSe2 combined with inevitable suppression of the Cooper pair density at the superconductor-vacuum interface. Our experimental results for N > 2 are in good agreement with the dependences of Δ and TC expected in the latter case while the effect of band-structure reconstruction is evidenced by a stronger suppression of Δ and the disappearance of its anisotropy for N = 2. The spatial scale involved in the surface suppression of the density of states is only a few angstroms but cannot be ignored for atomically thin superconductors. [ABSTRACT FROM AUTHOR]

Published
2018
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42. Sociodemographic Correlates of Affordable Community Behavioral Health Treatment Facility Availability in Florida: A Cross-Sectional Study.

Author

Shrader CH, Westrick A, Vos SR, Perrino T, Kanamori MJ, Ter-Ghazaryan D, and Stoler J

Subjects
Humans, Cross-Sectional Studies, Florida, Hispanic or Latino, Residence Characteristics, Black or African American, Health Services Accessibility, Substance-Related Disorders therapy
Abstract

Behavioral health disorders such as mental disorders (MD) and substance use disorders (SUD) are epidemics in the US; however, the availability of treatment and prevention services remains low. This study assessed neighborhood-level sociodemographic attributes to characterize the availability of behavioral health treatment facilities in Florida. The American Community Survey and SAMHSA's Behavioral Health Treatment Locator were used to identify behavioral health treatment facilities in Florida and calculate their density by census tract. Spatial lag regression models were used to assess census tract-level correlates of facility density for 390 MD treatment facilities, 518 SUD facilities, and subsets of affordable MD and SUD facilities. Behavioral health treatment facility density was negatively associated with rurality and positively associated with the proportion of non-Latino Black, Latino, insured, and college-educated populations. Stark rural-urban disparities in behavioral health treatment availability present opportunities to prioritize telehealth and mobile interventions and improve treatment utilization., (© 2023. National Council for Mental Wellbeing.)

Published
2023
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43. Engineering Graphene Flakes for Wearable Textile Sensors via Highly Scalable and Ultrafast Yarn Dyeing Technique.

Author

Afroj S, Karim N, Wang Z, Tan S, He P, Holwill M, Ghazaryan D, Fernando A, and Novoselov KS

Abstract

Multifunctional wearable e-textiles have been a focus of much attention due to their great potential for healthcare, sportswear, fitness, space, and military applications. Among them, electroconductive textile yarn shows great promise for use as next-generation flexible sensors without compromising the properties and comfort of usual textiles. However, the current manufacturing process of metal-based electroconductive textile yarn is expensive, unscalable, and environmentally unfriendly. Here we report a highly scalable and ultrafast production of graphene-based flexible, washable, and bendable wearable textile sensors. We engineer graphene flakes and their dispersions in order to select the best formulation for wearable textile application. We then use a high-speed yarn dyeing technique to dye (coat) textile yarn with graphene-based inks. Such graphene-based yarns are then integrated into a knitted structure as a flexible sensor and could send data wirelessly to a device via a self-powered RFID or a low-powered Bluetooth. The graphene textile sensor thus produced shows excellent temperature sensitivity, very good washability, and extremely high flexibility. Such a process could potentially be scaled up in a high-speed industrial setup to produce tonnes (∼1000 kg/h) of electroconductive textile yarns for next-generation wearable electronics applications.

Published
2019
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44. Author Correction: Planar and van der Waals heterostructures for vertical tunnelling single electron transistors.

Author

Kim G, Kim SS, Jeon J, Yoon SI, Hong S, Cho YJ, Misra A, Ozdemir S, Yin J, Ghazaryan D, Holwill M, Mishchenko A, Andreeva DV, Kim YJ, Jeong HY, Jang AR, Chung HJ, Geim AK, Novoselov KS, Sohn BH, and Shin HS

Abstract

The original version of this Article contained an error in the spelling of the author Matthew Holwill, which was incorrectly given as Mathew Holwill. This has now been corrected in both the PDF and HTML versions of the Article.

Published
2019
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45. Planar and van der Waals heterostructures for vertical tunnelling single electron transistors.

Author

Kim G, Kim SS, Jeon J, Yoon SI, Hong S, Cho YJ, Misra A, Ozdemir S, Yin J, Ghazaryan D, Holwill M, Mishchenko A, Andreeva DV, Kim YJ, Jeong HY, Jang AR, Chung HJ, Geim AK, Novoselov KS, Sohn BH, and Shin HS

Abstract

Despite a rich choice of two-dimensional materials, which exists these days, heterostructures, both vertical (van der Waals) and in-plane, offer an unprecedented control over the properties and functionalities of the resulted structures. Thus, planar heterostructures allow p-n junctions between different two-dimensional semiconductors and graphene nanoribbons with well-defined edges; and vertical heterostructures resulted in the observation of superconductivity in purely carbon-based systems and realisation of vertical tunnelling transistors. Here we demonstrate simultaneous use of in-plane and van der Waals heterostructures to build vertical single electron tunnelling transistors. We grow graphene quantum dots inside the matrix of hexagonal boron nitride, which allows a dramatic reduction of the number of localised states along the perimeter of the quantum dots. The use of hexagonal boron nitride tunnel barriers as contacts to the graphene quantum dots make our transistors reproducible and not dependent on the localised states, opening even larger flexibility when designing future devices.

Published
2019
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46. Phonon-Assisted Resonant Tunneling of Electrons in Graphene-Boron Nitride Transistors.

Author

Vdovin EE, Mishchenko A, Greenaway MT, Zhu MJ, Ghazaryan D, Misra A, Cao Y, Morozov SV, Makarovsky O, Fromhold TM, Patanè A, Slotman GJ, Katsnelson MI, Geim AK, Novoselov KS, and Eaves L

Abstract

We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between 10 and 200 mV. We attribute them to electron tunneling assisted by the emission of phonons of well-defined energy. The bias voltages at which they occur are insensitive to the applied gate voltage and hence independent of the carrier densities in the graphene electrodes, so plasmonic effects can be ruled out. The phonon energies corresponding to the resonances are compared with the lattice dispersion curves of graphene-boron nitride heterostructures and are close to peaks in the single phonon density of states.

Published
2016
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47. Organization and operation of the marine ornamental fish and invertebrate export fishery in Puerto Rico.

Author

Legorel RS, Hardin MP, and Ter-Ghazaryan D

Subjects
Animals, Commerce economics, Ecosystem, Population Dynamics, Puerto Rico, Time Factors, Commerce organization & administration, Conservation of Natural Resources legislation & jurisprudence, Fisheries economics, Fishes, International Cooperation, Invertebrates
Abstract

This fishery was examined utilizing public records, stakeholder interviews, and operational site visits to describe the fishery for the Puerto Rico Coral Reef Advisory Committee as a first step toward development of policies for the effective management of these natural resources. The fishery is not large, including fewer than 20 licensed fishers operating primarily on the west end of the island. Only three operators export product, with the remaining fishers providing specimens to the exporters based upon customer orders. Most collection of coral reef species occurs over hard rubble zones mixed with relic reef structures and rock, or on the sides and frontal areas of active reefs. Other species are collected from among mangrove prop root zones, tidal flats, and seagrass beds. Collections are made using simple barrier and dip nets for fish and motile invertebrates such as shrimp. Invertebrates such as crabs, starfish, and sea cucumbers are commonly collected by overturning small rocks, gathering the specimens, and then replacing the rocks in their original positions. Specimens are carried to the boat and transferred to individual cup holders to maximize survival. Although statements concerning former use of chemicals to assist capture were noted, no evidence of current chemical use was observed. Specimens are held in re-circulating seawater systems onshore until collections are aggregated and shipped. The fishery strives to operate with mortality of<1%, as mortalities of>3% are described as unacceptable to customers. More than 100 fish species are collected in this fishery, but the top ten species account for >70% of the total numbers and >60% of the total value of the fishery, with a single species, Gramma loreto (Royal Gramma), comprising >40% of the numbers. More than 100 species of invertebrates are collected, but this fishery is also dominated by a handful of species, including anemones, hermit crabs, turbo snails, serpent starfish, and feather duster polychaetes.

Published
2005

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