Dynamical l-bits in Stark many-body localization

TL;DR

This paper introduces the concept of dynamical l-bits in Stark many-body localized systems, providing analytical proofs and numerical confirmation of their stability, localization, and quantum coherence, with implications for quantum information processing.

Contribution

It rigorously proves the existence of dynamical l-bits in Stark MBL systems, explaining observed phenomena and demonstrating their stability and coherence at infinite temperature.

Findings

Existence of exponentially stable dynamical l-bits in Stark MBL.

Persistence of many-body Bloch oscillations at infinite temperature.

Numerical confirmation in tilted XXZ spin chain model.

Abstract

Stark many-body localized (SMBL) systems have been shown both numerically and experimentally to have Bloch many-body oscillations, quantum many-body scars, and fragmentation in the large field tilt limit. Likewise, they are believed to show localization similar to disordered MBL. We explain and analytically prove all these observations by rigorously showing the existence of novel algebraic structures that are exponentially stable in time, which we call dynamical l-bits. Moreover, we show that many-body Bloch oscillations persist even at infinite temperature for exponentially long-times. We numerically confirm our results by studying the prototypical Stark MBL model of a tilted XXZ spin chain. Our work explains why thermalization was observed in a recent 2D tilted experiment. As dynamical l-bits are stable, localized and quantum coherent excitations, our work opens new possibilities for quantum information processing in Stark MBL systems.