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Gorbar EV, Gusynin VP, Parymuda MR. Reduced QED with Few Planes and Fermion Gap Generation. ENTROPY (BASEL, SWITZERLAND) 2023; 25:1317. [PMID: 37761616 PMCID: PMC10528318 DOI: 10.3390/e25091317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/05/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023]
Abstract
The formalism of reduced quantum electrodynamics is generalized to the case of heterostructures composed of a few atomically thick layers, and the corresponding effective (2+1)-dimensional gauge theory is formulated. This dimensionally reduced theory describes charged fermions confined to N planes and contains N vector fields with Maxwell's action modified by non-local form factors whose explicit form is determined. Taking into account the polarization function, the explicit formulae for the screened electromagnetic interaction are presented in the case of two and three layers. For a heterostructure with two atomically thick layers and charged fermions described by the massless Dirac equation, the dynamical gap generation of the excitonic type is studied. It is found that additional screening due to the second layer increases the value of the critical coupling constant for the gap generation compared to that in graphene.
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Affiliation(s)
- Eduard V. Gorbar
- Department of Physics, Taras Shevchenko National Kyiv University, 03022 Kyiv, Ukraine; (E.V.G.); (M.R.P.)
- Bogolyubov Institute for Theoretical Physics, 03143 Kyiv, Ukraine
| | | | - Maxim R. Parymuda
- Department of Physics, Taras Shevchenko National Kyiv University, 03022 Kyiv, Ukraine; (E.V.G.); (M.R.P.)
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2
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Bandurin DA, Principi A, Phinney IY, Taniguchi T, Watanabe K, Jarillo-Herrero P. Interlayer Electron-Hole Friction in Tunable Twisted Bilayer Graphene Semimetal. PHYSICAL REVIEW LETTERS 2022; 129:206802. [PMID: 36461999 DOI: 10.1103/physrevlett.129.206802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 08/22/2022] [Accepted: 10/21/2022] [Indexed: 06/17/2023]
Abstract
Charge-neutral conducting systems represent a class of materials with unusual properties governed by electron-hole (e-h) interactions. Depending on the quasiparticle statistics, band structure, and device geometry these semimetallic phases of matter can feature unconventional responses to external fields that often defy simple interpretations in terms of single-particle physics. Here we show that small-angle twisted bilayer graphene (SA TBG) offers a highly tunable system in which to explore interactions-limited electron conduction. By employing a dual-gated device architecture we tune our devices from a nondegenerate charge-neutral Dirac fluid to a compensated two-component e-h Fermi liquid where spatially separated electrons and holes experience strong mutual friction. This friction is revealed through the T^{2} resistivity that accurately follows the e-h drag theory we develop. Our results provide a textbook illustration of a smooth transition between different interaction-limited transport regimes and clarify the conduction mechanisms in charge-neutral SA TBG.
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Affiliation(s)
- D A Bandurin
- Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore
| | - A Principi
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - I Y Phinney
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute of Material Science, Tsukuba 305-0044, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute of Material Science, Tsukuba 305-0044, Japan
| | - P Jarillo-Herrero
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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3
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Escudero F, Ardenghi JS. Cavity-mediated drag in double-layer graphene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:395602. [PMID: 35839734 DOI: 10.1088/1361-648x/ac8195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
We study the frictional drag between two graphene layers placed inside a cavity. We show that the drag has two contributions: the well-known Coulomb drag, and a novel photon-mediated drag. The latter arises from a cavity-mediated interaction in which the backscattering is not suppressed and the screening is relatively weak. As a result, the photon-mediated drag resistivity in the Fermi-liquid regime acquires corrections to the usual quadratic temperature dependence, has a slow decay as the interlayer separationdincreases, and depends on the carrier densitynasρD∼1/n2. Thus, whereas for smalldandnthe Coulomb drag dominates, as these parameters increase the drag transitions to a purely photon-mediated drag. The onset of this transition depends on the electromagnetic field enhancement inside the cavity.
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Affiliation(s)
- F Escudero
- Departamento de Física, Universidad Nacional del Sur, Av. Alem 1253, B8000 Bahía Blanca, Argentina
- Instituto de Física del Sur (IFISUR, UNS-CONICET), Av. Alem 1253, B8000 Bahía Blanca, Argentina
| | - J S Ardenghi
- Departamento de Física, Universidad Nacional del Sur, Av. Alem 1253, B8000 Bahía Blanca, Argentina
- Instituto de Física del Sur (IFISUR, UNS-CONICET), Av. Alem 1253, B8000 Bahía Blanca, Argentina
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4
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Liu H, MacDonald AH, Efimkin DK. Anomalous Drag in Electron-Hole Condensates with Granulated Order. PHYSICAL REVIEW LETTERS 2021; 127:166801. [PMID: 34723582 DOI: 10.1103/physrevlett.127.166801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
We explain the strong interlayer drag resistance observed at low temperatures in bilayer electron-hole systems in terms of an interplay between local electron-hole-pair condensation and disorder-induced carrier density variations. Smooth disorder drives the condensate into a granulated phase in which interlayer coherence is established only in well-separated and disconnected regions, or grains, within which the densities of electrons and holes accidentally match. The drag resistance is then dominated by Andreev-like scattering of charge carriers between layers at the grains that transfers momentum between layers. We show that this scenario can account for the observed dependence of the drag resistivity on temperature and, on average, charge imbalance between layers.
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Affiliation(s)
- Hong Liu
- School of Physics and Astronomy, Monash University, Victoria 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria 3800, Australia
| | - Allan H MacDonald
- Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712-1192, USA
| | - Dmitry K Efimkin
- School of Physics and Astronomy, Monash University, Victoria 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria 3800, Australia
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Rabinowitz J, Cohen C, Shepard KL. An Electrically Actuated, Carbon-Nanotube-Based Biomimetic Ion Pump. NANO LETTERS 2020; 20:1148-1153. [PMID: 31877247 PMCID: PMC7018576 DOI: 10.1021/acs.nanolett.9b04552] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Single-walled carbon nanotubes (SWCNTs) are well-established transporters of electronic current, electrolyte, and ions. In this work, we demonstrate an electrically actuated biomimetic ion pump by combining these electronic and nanofluidic transport capabilities within an individual SWCNT device. Ion pumping is driven by a solid-state electronic input, as Coulomb drag coupling transduces electrical energy from solid-state charge along the SWCNT shell to electrolyte inside the SWCNT core. Short-circuit ionic currents, measured without an electrolyte potential difference, exceed 1 nA and scale larger with increasing ion concentrations through 1 M, demonstrating applicability under physiological (∼140 mM) and saltwater (∼600 mM) conditions. The interlayer coupling allows ionic currents to be tuned with the source-drain potential difference and electronic currents to be tuned with the electrolyte potential difference. This combined electronic-nanofluidic SWCNT device presents intriguing applications as a biomimetic ion pump or component of an artificial membrane.
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Affiliation(s)
- Jake Rabinowitz
- Department of Electrical Engineering, Columbia University, NY 10027, USA
| | - Charishma Cohen
- Department of Electrical Engineering, Columbia University, NY 10027, USA
| | - Kenneth L. Shepard
- Department of Electrical Engineering, Columbia University, NY 10027, USA
- Department of Biomedical Engineering, Columbia University, NY 10027, USA
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Berdanier W, Scaffidi T, Moore JE. Energy Drag in Particle-Hole Symmetric Systems as a Quantum Quench. PHYSICAL REVIEW LETTERS 2019; 123:246603. [PMID: 31922879 DOI: 10.1103/physrevlett.123.246603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Indexed: 06/10/2023]
Abstract
Two conducting quantum systems coupled only via interactions can exhibit the phenomenon of Coulomb drag, in which a current passed through one layer can pull a current along in the other. However, in systems with particle-hole symmetry-for instance, the half filled Hubbard model or graphene near the Dirac point-the Coulomb drag effect vanishes to leading order in the interaction. Its thermal analog, whereby a thermal current in one layer pulls a thermal current in the other, does not vanish and is indeed the dominant form of drag in particle-hole symmetric systems. By studying a quantum quench, we show that thermal drag, unlike charge drag, displays a non-Fermi's golden rule growth at short times due to a logarithmic scattering singularity generic to one dimension. Exploiting the integrability of the Hubbard model, we obtain the long-time limit of the quench for weak interactions. Finally, we comment on thermal drag effects in higher dimensional systems.
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Affiliation(s)
- William Berdanier
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Thomas Scaffidi
- Department of Physics, University of California, Berkeley, California 94720, USA
- Department of Physics, University of Toronto, Toronto, Ontario, M5S 1A7, Canada
| | - Joel E Moore
- Department of Physics, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Tse WK, Hu BYK, Hong JN, MacDonald AH. Magneto-Coulomb Drag and Hall Drag in Double-Layer Dirac Systems. PHYSICAL REVIEW LETTERS 2019; 122:186602. [PMID: 31144885 DOI: 10.1103/physrevlett.122.186602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 08/03/2018] [Indexed: 06/09/2023]
Abstract
We develop a theory of Coulomb drag due to momentum transfer between graphene layers in a strong magnetic field. The theory is intended to apply in systems with disorder that is weak compared to Landau level separation, so that Landau level mixing is weak but strong compared to correlation energies within a single Landau level, so that fractional quantum Hall physics is not relevant. We find that, in contrast to the zero-field limit, the longitudinal magneto-Coulomb drag is finite and, in fact, attains a maximum at the simultaneous charge neutrality point (CNP) of both layers. Our theory also predicts a sizable Hall drag resistivity at densities away from the CNP.
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Affiliation(s)
- Wang-Kong Tse
- Department of Physics and Astronomy, Center for Materials for Information Technology, The University of Alabama, Alabama 35487, USA
| | - Ben Yu-Kuang Hu
- Department of Physics, The University of Akron, Akron, Ohio 44325, USA
| | - J N Hong
- Department of Physics and Astronomy, Center for Materials for Information Technology, The University of Alabama, Alabama 35487, USA
| | - A H MacDonald
- Department of Physics, University of Texas, Austin, Texas 78712, USA
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Li JIA, Taniguchi T, Watanabe K, Hone J, Levchenko A, Dean CR. Negative Coulomb Drag in Double Bilayer Graphene. PHYSICAL REVIEW LETTERS 2016; 117:046802. [PMID: 27494491 DOI: 10.1103/physrevlett.117.046802] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Indexed: 06/06/2023]
Abstract
We report on an experimental measurement of Coulomb drag in a double quantum well structure consisting of bilayer-bilayer graphene, separated by few layer hexagonal boron nitride. At low temperatures and intermediate densities, a novel negative drag response with an inverse sign is observed, distinct from the momentum and energy drag mechanisms previously reported in double monolayer graphene. By varying the device aspect ratio, the negative drag component is suppressed and a response consistent with pure momentum drag is recovered. In the momentum drag dominated regime, excellent quantitative agreement with the density and temperature dependence predicted for double bilayer graphene is found.
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Affiliation(s)
- J I A Li
- Department of Physics, Columbia University, New York, New York 10027, USA
| | - T Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
| | - K Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
| | - J Hone
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA
| | - A Levchenko
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - C R Dean
- Department of Physics, Columbia University, New York, New York 10027, USA
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Titov M, Gorbachev RV, Narozhny BN, Tudorovskiy T, Schütt M, Ostrovsky PM, Gornyi IV, Mirlin AD, Katsnelson MI, Novoselov KS, Geim AK, Ponomarenko LA. Giant magnetodrag in graphene at charge neutrality. PHYSICAL REVIEW LETTERS 2013; 111:166601. [PMID: 24182287 DOI: 10.1103/physrevlett.111.166601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Indexed: 06/02/2023]
Abstract
We report experimental data and theoretical analysis of Coulomb drag between two closely positioned graphene monolayers in a weak magnetic field. Close enough to the neutrality point, the coexistence of electrons and holes in each layer leads to a dramatic increase of the drag resistivity. Away from charge neutrality, we observe nonzero Hall drag. The observed phenomena are explained by decoupling of electric and quasiparticle currents which are orthogonal at charge neutrality. The sign of magnetodrag depends on the energy relaxation rate and geometry of the sample.
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Affiliation(s)
- M Titov
- Radboud University Nijmegen, Institute for Molecules and Materials, NL-6525 AJ Nijmegen, Netherlands
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