Chiral magnetic effect (CME) at low temperature from instanton vacuum

TL;DR

This paper investigates the chiral magnetic effect at low temperatures using the instanton vacuum model, revealing the dependence on topological charge and the diminishing effect with increasing temperature.

Contribution

It introduces a novel approach to study CME at low temperature via instanton fluctuations, highlighting the topological charge's role and temperature effects.

Findings

Longitudinal electromagnetic current exceeds transverse current.

Chiral charge density equals the magnitude of certain electromagnetic current components.

CME effect diminishes as temperature increases due to reduced instanton effects.

Abstract

In this talk, we report our present work on the chiral magnetic effect (CME) under a strong magnetic field at low temperature. To this end, we use the instanton vacuum with the finite instanton-number fluctuation Delta, which relates to the nontrivial topological charge Q_t. We compute the vacuum expectation values of the local chiral density <rho_chi>, chiral charge density <n_chi> and induced electromagnetic current <j_mu>. We observed that the longitudinal EM current is much larger than the transverse one, |j_perp/j_parallel| ~ Q_t, and the <n_chi> equals to the |<j_(3,4)>|. It also turns out that the CME becomes insensitive to the magnetic field as T increases, since the instanton effect decreases.