Chiral Plasma under Strong Magnetic Fields: A Holographic Analysis of Transport Phenomena

Abstract

Chiral plasma appears in several areas of physics, historically starting from primordial plasma in the early Universe, then in quark-gluon plasma produced in heavy ion collisions, and, more recently, in Dirac and Weyl semimetals. The major signature of the plasma is the non-conservation of the axial current due to the chiral anomaly and the emergence of new, anomaly-induced transport phenomena. In this paper, we study the plasma exposed to arbitrarily strong constant magnetic and weak electric fields. Employing all-order gradient resummation, we write down constitutive relations for electric and axial currents parameterized by thirteen momentum- and magnetic- field-dependent transport coefficient functions. The latter are computed utilizing a theoretical lab for a realistic plasma, namely a holographic $U(1)_V \times U(1)_A$ Maxwell--Chern--Simons theory in Schwarzschild--AdS$_5$, in the probe limit. As an application, we revisit the phenomena of negative magnetoresistance and chiral magnetic waves, beyond the naive hydrodynamic limit.