Hydrodynamic thermoelectric transport in Corbino geometry

TL;DR

This paper investigates hydrodynamic electron flow in Corbino graphene devices, revealing unique thermoelectric phenomena such as boundary voltage drops and a Lorentzian density dependence of thermal conductance, enabling viscosity measurement.

Contribution

It introduces a theoretical framework for thermoelectric transport in Corbino geometry, highlighting effects of force expulsion and non-Galilean invariance on measurable properties.

Findings

Voltage and temperature drops occur at system boundaries.

Thermal conductance shows Lorentzian dependence on electron density.

Thermoelectric response violates classical transport laws.

Abstract

We study hydrodynamic electron transport in Corbino graphene devices. Due to the irrotational character of the flow, the forces exerted on the electron liquid are expelled from the bulk. We show that in the absence of Galilean invariance, force expulsion produces qualitatively new features in thermoelectric transport: (i) it results in drops of both voltage and temperature at the system boundaries and (ii) in conductance measurements in pristine systems, the electric field is not expelled from the bulk. We obtain thermoelectric coefficients of the system in the entire crossover region between charge neutrality and high electron density regime. The thermal conductance exhibits a sensitive Lorentzian dependence on the electron density. The width of the Lorentzian is determined by the fluid viscosity. This enables determination of the viscosity of electron liquid near charge neutrality from purely thermal transport measurements. In general, the thermoelectric response is anomalous: it violates the Matthiessen's rule, the Wiedemann-Franz law, and the Mott relation.