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arXiv 0909.3119cond-mat.str-elcond-mat.other
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用纠缠谱研究绝缘体的能带拓扑

Band Topology of Insulators via the Entanglement Spectrum

Ari M. Turner, Yi Zhang, Ashvin Vishwanath

摘要:

我们如何唯一地识别一个量子相位,给定它的基态波函数?这是许多物体理论的一个关键问题,特别是当我们考虑像拓扑绝缘体这样的相位时,它们具有相同的对称性,但在拓扑水平上不同。纠缠谱已经被提出作为捕获特征边缘激发的基态性质。本文研究了拓扑带绝缘体的纠缠谱。我们首先表明,具有拓扑表面态的绝缘体在纠缠谱中也必然具有受保护的模式。然而,令人惊讶的是,反过来并不正确。受保护的纠缠模式也可以出现在没有物理表面状态的绝缘体中,在这种情况下,它们捕获了一个更难以捉摸的属性。这是说明考虑绝缘体只有反转对称。反演示出的行为在一个不寻常的方式,作为一个反幺正运营商,纠缠谱,导致这种保护。纠缠简并表示各种不同的相位反转对称绝缘体,这些相位被认为是强大的相互作用的引入。

英文摘要:

How do we uniquely identify a quantum phase, given its ground state wave-function? This is a key question for many body theory especially when we consider phases like topological insulators, that share the same symmetry but differ at the level of topology. The entanglement spectrum has been proposed as a ground state property that captures characteristic edge excitations. Here we study the entanglement spectrum for topological band insulators. We first show that insulators with topological surface states will necessarily also have protected modes in the entanglement spectrum. Surprisingly, however, the converse is not true. Protected entanglement modes can also appear for insulators without physical surface states, in which case they capture a more elusive property. This is illustrated by considering insulators with only inversion symmetry. Inversion is shown to act in an unusual way, as an antiunitary operator, on the entanglement spectrum, leading to this protection. The entanglement degeneracies indicate a variety of different phases in inversion symmetric insulators, and these phases are argued to be robust to the introduction of interactions.

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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