Stability of many-body localization in Floquet systems

TL;DR

This paper investigates the stability of many-body localization in disordered Floquet systems, demonstrating that finite size effects are less severe than in traditional models, and providing evidence for a phase transition with a critical exponent near 2.

Contribution

The study introduces a polynomially filtered exact diagonalization method for Floquet systems and shows reduced finite size effects in MBL transition analysis compared to conventional models.

Findings

Finite size effects are less severe in Floquet models.

Consistent signatures of MBL transition observed across indicators.

Critical exponent near 2 supports Harris criterion.

Abstract

We study many-body localization (MBL) transition in disordered Floquet systems using a polynomially filtered exact diagonalization (POLFED) algorithm. We focus on disordered kicked Ising model and quantitatively demonstrate that finite size effects at the MBL transition are less severe than in the random field XXZ spin chains widely studied in the context of MBL. Our conclusions extend also to other disordered Floquet models, indicating smaller finite size effects than those observed in the usually considered disordered autonomous spin chains. We observe consistent signatures of the transition to MBL phase for several indicators of ergodicity breaking in the kicked Ising model. Moreover, we show that an assumption of a power-law divergence of the correlation length at the MBL transition yields a critical exponent $\nu \approx 2$, consistent with the Harris criterion for 1D disordered systems.