Chiral hydrodynamics in strong external magnetic fields

TL;DR

This paper develops a comprehensive hydrodynamic framework for chiral fluids in strong magnetic fields, identifying new transport effects and calculating coefficients using holography.

Contribution

It introduces a general effective field theory approach for chiral hydrodynamics under magnetic fields, revealing four novel transport phenomena and deriving explicit coefficients.

Findings

Discovered shear-induced conductivity and Hall conductivity effects.

Derived 27 transport coefficients including new non-dissipative ones.

Computed coefficients explicitly in a strongly coupled quantum fluid via holography.

Abstract

We construct the general hydrodynamic description of (3+1)-dimensional chiral charged (quantum) fluids subject to a strong external magnetic field with effective field theory methods. We determine the constitutive equations for the energy-momentum tensor and the axial charge current, in part from a generating functional. Furthermore, we derive the Kubo formulas which relate two-point functions of the energy-momentum tensor and charge current to 27 transport coefficients: 8 independent thermodynamic, 4 independent non-dissipative hydrodynamic, and 10 independent dissipative hydrodynamic transport coefficients. Five Onsager relations render 5 more transport coefficients dependent. We uncover four novel transport effects, which are encoded in what we call the shear-induced conductivity, the two expansion-induced longitudinal conductivities and the shear-induced Hall conductivity. Remarkably, the shear-induced Hall conductivity constitutes a novel non-dissipative transport effect. As a demonstration, we compute all transport coefficients explicitly in a strongly coupled quantum fluid via holography.