Electronic viscosity and energy relaxation in neutral graphene

TL;DR

This paper investigates the hydrodynamic behavior of neutral graphene's Dirac fermions in a Corbino setup, revealing how energy relaxation and viscous effects influence resistance and temperature profiles, suggesting experimental observability of the Dirac fluid.

Contribution

It provides a hydrodynamic analysis of energy and charge flow in neutral graphene within Corbino geometry, highlighting the impact of energy relaxation on resistance and interface discontinuities.

Findings

Energy flow affects resistance via viscous dissipation.

Temperature and potential are discontinuous at interfaces.

Corbino geometry is suitable for observing Dirac fluid behavior.

Abstract

We explore hydrodynamics of Dirac fermions in neutral graphene in the Corbino geometry. In the absence of magnetic field, the bulk Ohmic charge flow and the hydrodynamic energy flow are decoupled. However, the energy flow does affect the overall resistance of the system through viscous dissipation and energy relaxation that has to be compensated by the work done by the current source. Solving the hydrodynamic equations, we find that local temperature and electric potential are discontinuous at the interfaces with the leads as well as the device resistance and argue that this makes Corbino geometry a feasible choice for an experimental observation of the Dirac fluid.