Physical Response Functions of Strongly Coupled Massive Quantum Liquids

TL;DR

This paper investigates the physical properties of strongly coupled massive quantum liquids using spectral functions derived from AdS/CFT correspondence, revealing temperature-independent behaviors and a crossover between baryon- and meson-dominated regimes.

Contribution

It introduces a new technique employing scaling behavior in the dual geometry to analyze spectral functions of dense, heavy fundamental matter in strongly coupled quantum liquids.

Findings

AC conductivity and quasi-particle spectrum are temperature-independent.

Parameters like relaxation time depend only on mass-to-density ratio.

Results show a crossover between baryon- and meson-dominated regimes.

Abstract

We study physical properties of strongly coupled massive quantum liquids from their spectral functions using the AdS/CFT correspondence. The generic model that we consider is dense, heavy fundamental matter coupled to SU(N_c) super Yang-Mills theory at finite temperature above the deconfinement phase transition but below the scale set by the baryon number density. In this setup, we study the current-current correlators of the baryon number density using new techniques that employ a scaling behavior in the dual geometry. Our results, the AC conductivity, the quasi-particle spectrum and the Drude-limit parameters like the relaxation time are simple temperature-independent expressions that depend only on the mass-squared to density ratio and display a crossover between a baryon- and meson-dominated regime. We concentrated on the (2+1)-dimensional defect case, but in principle our results can also be generalized straightforwardly to other cases.