arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2108.03142cond-mat.dis-nncond-mat.quant-gascond-mat.str-el
收藏

粒子涨落和多体局域相简单有效模型的失效

Particle fluctuations and the failure of simple effective models for many-body localized phases

Maximilian Kiefer-Emmanouilidis, Razmik Unanyan, Michael Fleischhauer, Jesko Sirker

摘要:

本文研究并比较了在无相互作用情况下(安德森局域化)和只保留安德森基对角项的有效模型中,具有势无序和最近邻相互作用的无自旋费米子模型的假定多体局域化(MBL)相的粒子数涨落.我们证明,这些类型的简单有效的模型不能占的微观模型的MBL阶段中观察到的粒子数波动。这意味着,辅助和对跳跃项--时产生的微观哈密顿转换成安德森基础-不能忽略。因此,如果微观模型具有指数数量的完全守恒的局部电荷,这似乎是值得怀疑的。如果这种完全守恒的局域电荷不存在,那么粒子最终将在任何有限无序强度下离域。

英文摘要:

We investigate and compare the particle number fluctuations in the putative many-body localized (MBL) phase of a spinless fermion model with potential disorder and nearest-neighbor interactions with those in the non-interacting case (Anderson localization) and in effective models where only interaction terms diagonal in the Anderson basis are kept. We demonstrate that these types of simple effective models cannot account for the particle number fluctuations observed in the MBL phase of the microscopic model. This implies that assisted and pair hopping terms---generated when transforming the microscopic Hamiltonian into the Anderson basis---cannot be neglected. As a consequence, it appears questionable if the microscopic model possesses an exponential number of exactly conserved local charges. If such exactly conserved local charges do not exist, then particles are expected to ultimately delocalize for any finite disorder strength.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑