Dynamical instability and transport peak of chiral matter from holography

TL;DR

This paper investigates the dynamical behavior of strongly coupled chiral matter using holography, revealing instabilities, mode transitions, and transport peaks associated with phase transitions and chiral symmetry dynamics.

Contribution

It demonstrates the existence of dynamical instabilities, mode transitions, and transport peaks in chiral matter within a holographic framework, linking these phenomena to phase transitions and symmetry breaking.

Findings

Perturbations on unstable backgrounds show dynamic instability.

Identification of purely imaginary diffusive modes in the spectrum.

Transition from diffusive to propagating modes with increasing momentum.

Abstract

We study dynamical properties of strongly coupled chiral matter by using holographic method. We demonstrate, at both linear and nonlinear levels, that perturbations on thermodynamically unstable backgrounds within the spinodal region of chiral first-order phase transitions exhibit dynamic instability. The corresponding magnitude of dynamic instability can be characterized by the critical momentum. Furthermore, we found that, within a certain temperature range, the quasi-normal mode spectrum contains purely imaginary diffusive modes. As spatial momentum increases, a transition occurs in the system's long-time dynamics. The dominant contribution shifts from diffusive mode to propagating mode. When the diffusive mode becomes dominant, the spectral function exhibits a transport peak structure in the low-frequency region. A heuristic argument suggests that this particular transition can be related to the chiral symmetry breaking and restoration.