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arXiv 1001.5280math-phmath.MP
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无序系统的准绝热延拓:应用于关联、Lieb-Schultz-Mattis和Hall电导

Quasi-adiabatic Continuation for Disordered Systems: Applications to Correlations, Lieb-Schultz-Mattis, and Hall Conductance

M. B. Hastings

摘要:

我们提出了一个可能的定义的多体量子系统的迁移率间隙,在类似的单粒子系统的动力学局域化的定义。利用这个定义,我们构造了“修正的”准绝热延拓算子。在一个合适的定义下,一个独特的基态,我们展示了如何引入虚通量。有了这些结果,我们就可以直接在有谱隙的情况下推广以前的结果。我们提出了一个衰减的关联函数的证明,我们提出了一个证明霍尔电导量子化下非常温和的状态密度的假设后定义。我们还概括了这些定义的情况下,一个“批量迁移率间隙”,在一个系统的情况下的边界,并提出了一个证明的霍尔电导量子化的环在适当的假设。此外,我们提出了一个新的“优化”的准绝热连续算子,简化了以前的估计,并在某些情况下收紧界限。这是在附录中提出的,可以独立于论文的其余部分阅读,因为它也改善了具有谱隙的系统的估计。对于所有$α<1$,所使用的滤波器函数在时间上的衰减至少与${\cal O}(\exp(-t^α))$一样快,这是一类称为次指数的衰减(下文对可能的情况进行了更严格的描述)。使用此功能,它是可能的收紧最近的估计霍尔电导量子化的带隙系统\cite{hall}的衰减是次指数的系统大小。

英文摘要:

We present a possible definition of a mobility gap for a many-body quantum system, in analogy to definitions of dynamical localization for single particle systems. Using this definition, we construct "corrected" quasi-adiabatic continuation operators. Under an appropriate definition of a unique ground state, we show how to introduce virtual fluxes. Armed with these results, we can directly carry over previous results in the case of a spectral gap. We present a proof of decay of correlation functions and we present a proof of Hall conductance quantization under very mild density-of-states assumptions defined later. We also generalize these definitions to the case of a "bulk mobility gap", in the case of a system with boundaries, and present a proof of Hall conductance quantization on an annulus under appropriate assumptions. Further, we present a new "optimized" quasi-adiabatic continuation operator which simplifies previous estimates and tightens bounds in certain cases. This is presented in an appendix which can be read independently of the rest of the paper as it also improves estimates in the case of systems with a spectral gap. This filter function used decays in time at least as fast as ${\cal O}(\exp(-t^α))$ for all $α<1$, a class of decay called subexponential (a tighter description of what is possible is below). Using this function it is possible to tighten recent estimates of the Hall conductance quantization for gapped systems\cite{hall} to a decay which is subexponential in system size.

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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