Chiral phase transitions and quantum critical points of the D3/D7(D5) system with mutually perpendicular E and B fields at finite temperature and density

TL;DR

This paper investigates how chiral symmetry is affected by temperature, density, and perpendicular electric and magnetic fields in holographic gauge theories, revealing complex phase transition behaviors including BKT and mean-field types.

Contribution

It provides a detailed holographic analysis of chiral phase transitions in D3/D7 and D3/D5 systems under mutually perpendicular E and B fields at finite temperature and density, highlighting new transition phenomena.

Findings

D3/D5 system exhibits BKT phase transitions at zero temperature.

D3/D7 system shows mean-field phase transitions.

Transition order varies with temperature and density.

Abstract

We study chiral symmetry restoration with increasing temperature and density in gauge theories subject to mutually perpendicular electric and magnetic fields using holography. We determine the chiral symmetry breaking phase structure of the D3/D7 and D3/D5 systems in the temperature-density-electric field directions. A magnetic field may break the chiral symmetry and an additional electric field induces Ohm and Hall currents as well as restoring the chiral symmetry. At zero temperature the D3/D5 system displays a line of holographic BKT phase transitions in the density-electric field plane, while the D3/D7 system shows a mean-field phase transition. At intermediate temperatures, the transitions in the density-electric field plane are of first order at low density, transforming to second order at critical points as density rises. At high temperature the transition is only ever first order.