Drag suppression in anomalous chiral media

Abstract

We study a heavy impurity moving longitudinal with the direction of an external magnetic field in an anomalous chiral medium. Such system would carry a nondissipative current of chiral magnetic effect associated with the anomaly. We show, by generalizing Landau's criterion for superfluidity, that the "anomalous component" which gives rise to the anomalous transport will not contribute to the drag experienced by an impurity. We argue on a very general basis that those systems with a strong magnetic field would exhibit an interesting transport phenomenon-the motion of the heavy impurity is frictionless, in analogy to the case of a superfluid. We demonstrate and confirm our general results with two complementary examples: weakly coupled chiral fermion gases and strongly interacting chiral liquids.

Heavy-Quark Diffusion Dynamics in Quark–Gluon Plasma under Strong Magnetic Fields

“…The key observation was the kinematical constraint for the momentum transfer in the LLL, which prohibits the longitudinal momentum transfer in the massless limit [3,8].…”

“…2). We shall consider the massless fermions in the lowest Landau level [3,8]. For the massless quarks to be on-shell both in the initial and final states, the energy transfer has to be q 0 = ±(k z − k z ), and thus q 0 = ±q z .…”

Nonlocal transport in Weyl semimetals in the hydrodynamic regime

“…The above coefficients agree with those obtained in Refs. [48][49][50] in the "no-drag" frame [50][51][52]. Let us briefly comment on the physical meaning of the terms in the electric current (6).…”

Consistent hydrodynamic theory of chiral electrons in Weyl semimetals

“…The coefficients σ (B) and σ (ǫ,B) agree with those obtained in Refs. [25,34,35] in the "no-drag" frame [35][36][37]. We would like to point out that the Chern-Simons terms ρ CS and j CS do not directly contribute to the hydrodynamic parts of the charge and current densities in the Euler equation (5) and the energy conservation relation (6).…”