Symmetry and dynamics universality of supermetal in quantum chaos

TL;DR

This paper demonstrates that the transition from metal to supermetal behavior in quantum chaotic systems is universal and solely determined by symmetry, aligning with predictions from random matrix theory.

Contribution

It analytically and numerically establishes the universal symmetry-dependent crossover between metal and supermetal dynamics in quantum chaos.

Findings

Universal metal-supermetal crossover confirmed

Crossover determined solely by system symmetry

Matching eigenfunction and spectral fluctuation universality

Abstract

Chaotic systems exhibit rich quantum dynamical behaviors ranging from dynamical localization to normal diffusion to ballistic motion. Dynamical localization and normal diffusion simulate electron motion in an impure crystal with a vanishing and finite conductivity, i.e., an "Anderson insulator" and a "metal", respectively. Ballistic motion simulates a perfect crystal with diverging conductivity, i.e., a "supermetal". We analytically find and numerically confirm that, for a large class of chaotic systems, the metal-supermetal dynamics crossover occurs and is universal, determined only by the system's symmetry. Furthermore, we show that the universality of this dynamics crossover is identical to that of eigenfunction and spectral fluctuations described by the random matrix theory.