Chiral Hall Effect and Chiral Electric Waves

TL;DR

This paper explores the chiral Hall effect and chiral electric waves in chiral systems, revealing new transport phenomena and charge distributions influenced by electromagnetic fields and chemical potentials, with implications for heavy ion collisions.

Contribution

It introduces the concept of the chiral Hall effect and analyzes chiral electric waves using holographic methods, highlighting their properties and potential experimental signatures.

Findings

Discovery of the axial Hall current in chiral systems.

Identification of non-dissipative Hall density waves.

Calculation of transport coefficients in strongly coupled plasma.

Abstract

We investigate the vector and axial currents induced by external electromagnetic fields and chemical potentials in chiral systems at finite temperature. Similar to the normal Hall effect, we find that an axial Hall current is generated in the presence of the electromagnetic fields along with an axial chemical potential, which may be dubbed as the "chiral Hall effect"(CHE). The CHE is related to the interactions of chiral fermions and exists with the a nonzero axial chemical potential. We argue that the CHE could lead to nontrivial charge distributions at different rapidity in asymmetric heavy ion collisions. Moreover, we study the chiral electric waves(CEW) led by the fluctuations of the vector and axial chemical potentials along with the chiral electric separation effect(CESE), where a density wave propagates along the applied electric field. Combining with the normal/chiral Hall effects, the fluctuations of chemical potentials thus result in Hall density waves. The Hall density waves may survive even at zero chemical potentials and become non-dissipative. We further study the transport coefficients including the Hall conductivities, damping times, wave velocities, and diffusion constants of CEW in a strongly coupled plasma via the AdS/CFT correspondence.