Avalanche stability transition in interacting quasiperiodic systems

TL;DR

This study investigates the stability of many-body localization in quasiperiodic systems, revealing they are more resilient to avalanche instabilities than random disordered systems, with implications for understanding different universality classes.

Contribution

It demonstrates that quasiperiodic systems exhibit greater MBL stability than random systems and introduces real space RG arguments to support this finding.

Findings

MBL is more stable in quasiperiodic systems for W>8

Quasiperiodic and random MBL belong to different universality classes

Potential for MBL stability at arbitrarily large system sizes in quasiperiodic systems

Abstract

Coupling a 1D quasiperiodic interacting system to a Markovian bath, we study the avalanche instability of the many body localized phase numerically, finding that many body localization (MBL) is more stable in pseudorandom quasiperiodic systems than the corresponding randomly disordered systems for a disorder strength $W>8$, potentially up to arbitrarily large system sizes. We support our conclusion by additionally developing real space RG arguments, and provide a detailed comparison between quasiperiodic and random MBL from the avalanche instability perspective, concluding that the two belong to different universality classes.