A Holographic Model For Hall Viscosity

TL;DR

This paper develops a holographic model with a charged black brane and a pseudoscalar field to demonstrate spontaneous parity breaking and the emergence of Hall viscosity in the boundary theory.

Contribution

It introduces a modified holographic setup with a charged black brane and a pseudoscalar potential including quadratic and quartic terms, enabling spontaneous parity breaking and Hall viscosity.

Findings

Spontaneous parity breaking occurs in the model.

Non-zero Hall viscosity is generated at the boundary.

The model extends previous neutral black brane holographic models.

Abstract

We have modified the holographic model of Saremi and Son by using a charged black brane, instead of a neutral one, such that when the bulk pseudo scalar potential is made of quadratic and quartic terms, parity can still be broken spontaneously in the boundary theory. In our model, the 3+1 dimensional bulk has a pseudo scalar coupled to the gravitational Chern-Simons term in the anti de Sitter charged black brane back ground. Parity could be broken spontaneously in the bulk by the pseudo scalar hairy solution and give rise to non-zero Hall viscosity at the boundary theory.