Nonlinear Chiral Transport Phenomena

TL;DR

This paper investigates nonlinear chiral transport phenomena in relativistic matter, revealing new electric currents driven by Berry curvature effects and deriving a Wiedemann-Franz law analogue for such systems.

Contribution

It introduces a novel nonlinear electric current proportional to the cross product of chemical potential gradient and electric field, expanding understanding of chiral transport.

Findings

Discovery of a new electric current term involving ${f abla} oldsymbol{f} imes {f E}$

Derivation of a Wiedemann-Franz law analogue for nonlinear chiral transport

Identification of transport coefficients enabled by Berry curvature and collisions

Abstract

We study the nonlinear responses of relativistic chiral matter to the external fields, such as the electric field ${\bf E}$, gradients of temperature and chemical potential, ${\bf \nabla} T$ and ${\bf \nabla} \mu$. Using the kinetic theory with Berry curvature corrections under the relaxation time approximation, we compute the transport coefficients of possible new electric currents that are forbidden in usual chirally symmetric matter, but are allowed in chirally asymmetric matter by parity. In particular, we find a new type of electric current proportional to ${\bf \nabla} \mu \times {\bf E}$ due to the interplay between the effects of the Berry curvature and collisions. We also derive an analogue of the "Wiedemann-Franz" law specific for anomalous nonlinear transport in relativistic chiral matter.