Coulomb drag driven electron-hole bifluidity in doped graphene

TL;DR

This paper investigates how Coulomb interactions in doped graphene can induce electron-hole bifluidity and hydrodynamic effects, revealing unique transport phenomena and violations of classical laws.

Contribution

It provides an ab initio analysis of charge transport in doped graphene, highlighting Coulomb drag effects leading to joint electron-hole hydrodynamics and identifying conditions for these phenomena.

Findings

Coulomb drag induces negative conductivity in doped graphene.

Electron-hole bifluidity occurs under specific conditions.

Strong violation of Wiedemann-Franz law in low doping regimes.

Abstract

Motivated by the notion that a preponderance of Coulomb interactions might lead to hydrodynamics, we carry out an ab initio calculation of the charge carrier transport properties of the electron-hole plasma of doped graphene. We include both the phonon and Coulomb interactions within a momentum and band resolved Boltzmann transport formalism. We find that, under suitable conditions, the strong Coulomb drag effect induces effects like negative conductivity and joint electron-hole hydrodynamics (bifluidity) in the plasma. We also identify the exclusive electron or hole hydrodynamics. We find that there is a strong violation of the Wiedemann-Franz law in the low doped regimes. Our work elucidates the roles of the microscopic scattering mechanisms that drive these hydrodynamic phenomena.