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arXiv 2103.06308cond-mat.stat-mechnlin.CD
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弱可积性破缺与能级间距分布

Weak integrability breaking and level spacing distribution

D. Szász-Schagrin, B. Pozsgay, G. Takács

AI总结:

本研究针对可积自旋链微扰引发的弱可积性破缺论断,通过能级间距分布检验发现,弱与强可积破缺下的体积依赖渡越特征差异显著,无隙情形下二者渡越耦合的体积标度律分别为$1/L^2$与$1/L^3$。

摘要:

近期有研究提出,可积自旋链的特定微扰会导致弱可积性破缺,即可积性在耦合的一阶近似下得以保留。本文利用能级间距分布对这一论断展开检验。研究发现,标志着量子混沌行为起始的、可积与混沌能级间距统计之间的体积依赖渡越,在弱可积破缺与强可积破缺情形下存在显著差异。具体而言,对于无隙情形,我们发现作为体积$L$函数的渡越耦合,在弱破缺下遵循$1/L^2$标度律,这与此前在强破缺情形下发现的$1/L^3$标度律形成对比。

英文摘要:

Recently it was suggested that certain perturbations of integrable spin chains lead to a weak breaking of integrability in the sense that integrability is preserved at the first order in the coupling. Here we examine this claim using level spacing distribution. We find that the volume dependent crossover between integrable and chaotic level spacing statistics which marks the onset of quantum chaotic behaviour, is markedly different for weak vs. strong breaking of integrability. In particular, for the gapless case we find that the crossover coupling as a function of the volume $L$ scales with a $1/L^2$ law for weak breaking as opposed to the $1/L^3$ law previously found for the strong case.

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。

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