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arXiv · 1607.07269

Higher-Than-Ballistic Conduction of Viscous Electron Flows

Haoyu Guo·Ekin Ilseven·Gregory Falkovich·Leonid Levitov
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Abstract

Strongly interacting electrons can move in a neatly coordinated way, reminiscent of the movement of viscous fluids. Here we show that in viscous flows interactions facilitate transport, allowing conductance to exceed the fundamental Landauer's ballistic limit $G_{\rm ball}$. The effect is particularly striking for the flow through a viscous point contact, a constriction exhibiting the quantum-mechanical ballistic transport at $T=0$ but governed by electron hydrodynamics at elevated temperatures. We develop a theory of the ballistic-to-viscous crossover using an approach based on quasi-hydrodynamic variables. Conductance is found to obey an additive relation $G=G_{\rm ball}+G_{\rm vis}$, where the viscous contribution $G_{\rm vis}$ dominates over $G_{\rm ball}$ in the hydrodynamic limit. We argue that superballistic, low-dissipation transport is a generic feature of viscous electronics.

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Haoyu Guo, Ekin Ilseven, Gregory Falkovich, Leonid Levitov. 2016-07-25. Higher-Than-Ballistic Conduction of Viscous Electron Flows. https://doi.org/10.1073/pnas.1612181114

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