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arXiv · 1708.02376

Tomographic Dynamics and Scale-Dependent Viscosity in Two-Dimensional Electron Systems

Patrick J Ledwith·Haoyu Guo·Andrey V Shytov·Leonid Levitov
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Abstract

Fermi gases in two dimensions display a surprising collective behavior originating from the head-on carrier collisions. The head-on processes dominate angular relaxation at not-too-high temperatures $T\ll T_F$ owing to the interplay of Pauli blocking and momentum conservation. As a result, a large family of excitations emerges, associated with the odd-parity harmonics of momentum distribution and having exceptionally long lifetimes. This leads to "tomographic" dynamics: fast 1D spatial diffusion along the unchanging velocity direction accompanied by a slow angular dynamics that gradually randomizes velocity orientation. The tomographic regime features an unusual hierarchy of time scales and scale-dependent transport coefficients with nontrivial fractional scaling dimensions, leading to fractional-power current flow profiles and unusual conductance scaling vs. sample width.

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Patrick J Ledwith, Haoyu Guo, Andrey V Shytov, Leonid Levitov. 2017-08-08. Tomographic Dynamics and Scale-Dependent Viscosity in Two-Dimensional Electron Systems. https://doi.org/10.1103/physrevlett.123.116601

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