Vorticity-induced negative nonlocal resistance in a viscous two-dimensional electron system

Hydrodynamic and viscous effects in electronic liquids are at the focus of much current research. Most intriguing is perhaps the non-dissipative Hall viscosity, which, due to its symmetry-protected topological nature, can help identify complex topological orders. In this work we study the effects of viscosity in general, and Hall viscosity in particular, on the dispersion relation of edge magnetoplasmons in 2D electronic systems. Using an extension of the standard Wiener-Hopf technique we derive a general solution to the problem, accounting for the long-range Coulomb potential. Among other features we find that on the edge viscosity affects the dispersion already to leading order in the wavevector, making edge modes better suited for its measurement as compared to their bulk counterparts.arXiv:1809.05847v2 [cond-mat.str-el]

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“…We have verified numerically that the Wiener-Hopf dispersion, Eqs. (22), indeed agrees with the direct solution outline above in this case.…”

Section: Discussionsupporting

confidence: 89%

Hall and dissipative viscosity effects on edge magnetoplasmons

Cohen

Goldstein

2018

Phys. Rev. B

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“…A small difference between these masses may result in extra plasmon damping due to relaxation of velocity modes by e-e collisions in non-parabolic bands [21]. The formal solution for polarizability is readily derived from generalized hydrodynamic system (4)(5). Denoting the elements of hydrodynamic matrix as M ij and components of generalized force vector as δF i , we find Π(q, ω) = 1 eδϕ…”

Section: Hydrodynamic Transport Regimementioning

confidence: 99%

Emission of plasmons by drifting Dirac electrons: A hallmark of hydrodynamic transport

Svintsov

2019

Phys. Rev. B

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Direct current in clean semiconductors and metals was recently shown to obey the laws of hydrodynamics in a broad range of temperatures and sample dimensions. However, the determination of frequency window for hydrodynamic phenomena remains challenging. Here, we reveal a phenomenon being a hallmark of high-frequency hydrodynamic transport, the Cerenkov emission of plasmons by drifting Dirac electrons. The effect appears in hydrodynamic regime only due to reduction of plasmon velocity by electron-electron collisions below the velocity of carrier drift. To characterize the Cerenkov effect quantitatively, we analytically find the high-frequency non-local conductivity of drifting Dirac electrons across the hydrodynamic-to-ballistic crossover. We find the growth rates of hydrodynamic plasmon instabilities in two experimentally relevant setups: parallel graphene layers and graphene covered by subwavelength grating, further showing their absence in ballistic regime. We argue that the possibility of Cerenkov emission is linked to singular structure of non-local conductivity of Dirac materials and is independent on specific dielectric environment.The realm of hydrodynamic transport spans at length scales exceeding the particle free path [1]. Experimental demarcation of hydrodynamics and ballistics is conveniently performed by measuring the flow through a pipe between two reservoirs. The flow through wide pipes is limited by viscosity (Poiseuille flow), while in narrower pipes it is limited by particle injection (Knudsen flow). Recently, similar experiments were performed in ultraclean solid-state systems, including thin metal wires [2], Weyl semimetals [3], GaAs-based quantum wells [4], and graphene [5-7]. They have revealed quite a broad window of temperatures and sample dimensions where electrons obey the laws of hydrodynamics [8] but not ballistics, as thought previously [9].While the place for dc hydrodynamic (HD) phenomena on temperature and length scales is established [10,11], the bounds for hydrodynamics on frequency scale are less probed [12]. Generally, electron-electron (e-e) collisions being the prerequisite of HD transport affect neither dc nor ac conductivity in uniform fields, though they may affect the properties of waves in solids -plasmons. Still, the spectra of plasmons in HD and ballistic regimes are almost identical as they are dictated by long-range Coulomb forces insensitive to microscopic details of e-e interactions [13,14]. The character of damping due to e-e scattering in ballistic and HD regimes is different [15,16], still, it is often masked by extrinsic damping.In this Letter, we theoretically reveal a plasmonic phenomenon serving as a hallmark of hydrodynamic transport, and is fully prohibited in collisionless ballistic regime. The effect is emission of plasmons by drifting Dirac electrons or, in other words, Cerenkov plasmon instability of electron drift. Our emphasis on Dirac electron systems, especially graphene, is motivated by numerous observations of hydrodynamic phenomena therein [5][6...

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“…Фононный гидродинамический транспорт в жидком гелии, диэлектриках, металлах и полупроводниках был достаточно детально теоретически и экспериментально изучен несколько десятилетий назад [2][3][4]. Однако гидродинамический режим электронного транспорта в проводниках был экспериментально открыт только недавно в новых ультрачистых материалах: квантовых ямах GaAs [5][6][7][8][9][10], моновалентном слоистом металле PdCoO 2 [11], объемном вейлевском металле WP 2 [12] и графене [13][14][15]. Эти экспериметальные открытия сопровождались интенсивным развитием теории [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31].…”

Section: Introductionunclassified

“…Этот эффект был объяснен с помощью гидродинамической модели, учитывающей зависимость коэффициентов вязкости электронов от магнитного поля и температуры [18]. Другим доказательством формирования вязкой электронной жидкости в графеновых и высокоподвижных квантовых ямах GaAs является наблюдение отрицательного нелокального сопротивления, связанного с образованием водоворотов в электронной жидкости [10][11][12][13][14][15][16][17][18][19].…”

Section: Introductionunclassified

Магнитозвуковые Волны В Двумерной Электронной Ферми-Жидкости

Алексеев¹

2019

Физика И Техника Полупроводников

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The properties of highly viscous fluids at high frequencies become similar to the properties of amorphous solids. In particular, it becomes possible to propagate not only longitudinal sound waves (plasmons for the case of an electron fluid), but also transverse sound waves associated with shear deformations. In this work, transverse sound waves at high frequencies in a twodimensional electron liquid in a magnetic field are studied. The consideration was carried out in the framework of the Landau Fermi-liquid model. It is shown that for a sufficiently large interaction between quasiparticles, the dynamics of excitations of a Fermi liquid is described by the equations of hydrodynamics. The Navier-Stokes equation and expressions for high-frequency shear viscosity coefficients are derived. Based on the equations obtained, the dispersion laws are calculated for transverse and longitudinal magnetosonic waves. It is shown that the cyclotron frequency, which enters in the viscosity coefficients and the dispersion law of transverse magnetosonic waves, is renormalized and typically becomes less than the usual cyclotron frequency, which determines the cyclotron resonance. The latter fact was apparently observed in the photoresistance of highly mobile GaAs quantum wells, in which two-dimensional electrons form a viscous fluid.

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Vorticity-induced negative nonlocal resistance in a viscous two-dimensional electron system

Cited by 73 publications

References 26 publications

Hall and dissipative viscosity effects on edge magnetoplasmons

Hall and dissipative viscosity effects on edge magnetoplasmons

Emission of plasmons by drifting Dirac electrons: A hallmark of hydrodynamic transport

Магнитозвуковые Волны В Двумерной Электронной Ферми-Жидкости

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