Interacting quasiperiodic spin chains in the prethermal regime
arxiv(2024)
摘要
Recent progress in the study of many-body localization (MBL) in strongly
disordered interacting spin chains has emphasized the importance of
distinguishing finite time prethermal behavior from long time and large volume
asymptotics. We re-examine a reported non-ergodic extended (NEE) regime in
quasiperiodically disordered chains from this perspective, and propose that
this regime is a prethermal feature. Indeed, we argue that the NEE regime may
be identified through a change in the functional form of spin-spin
autocorrelation functions, demonstrating that the NEE regime is distinguishable
within intermediate-time dynamics. This is in contrast with existing
conjectures relating the NEE regime to the presence of an asymptotic mobility
edge in the single-particle spectrum. Thus, we propose a mechanism for the
formation of an NEE regime which does not rely on asymptotic properties of the
spin chain. Namely, we propose that the NEE regime emerges due to regularly
spaced deep wells in the disorder potential. The highly detuned sites suppress
spin transport across the system, effectively cutting the chain, and producing
a separation of time scales between the spreading of different operators. To
support this proposal, we show that the NEE phenomenology also occurs in random
models with deep wells but with no mobility edges, and does not occur in
quasiperiodic models with mobility edges but with no deep wells. Our results
support the broad conclusion that there is not a sharp distinction between the
dynamics of quasiperiodically and randomly disordered systems in the prethermal
regime. More specifically, we find that generic interacting quasiperiodic
models do not have stable intermediate dynamical phases arising from their
single-particle mobility edges, and that NEE phenomenology in such models is
transient.
更多查看译文
AI 理解论文
溯源树
样例
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要