Non-Bloch band theory of non-Hermitian Hamiltonians in the symplectic class
Non-Bloch band theory of non-Hermitian Hamiltonians in the symplectic class
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DOI：
10.1103/physrevb.101.195147
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发表时间：
2020-05-29
影响因子：
3.7
通讯作者：
Sato, Masatoshi
中科院分区：
文献类型：
--
作者：
Kawabata, Kohei;Okuma, Nobuyuki;Sato, Masatoshi
非厄米哈密顿量一般对边界条件敏感，其在开放边界条件下的谱和波函数不一定能由周期性边界条件的布洛赫能带理论预测。为了阐明这种非布洛赫特征，最近的工作开发了一种非布洛赫能带理论，即使在任意边界条件下也能发挥作用。在这里，证明了标准的非布洛赫能带理论在辛类中崩溃，其中非厄米哈密顿量由于互易性而表现出克莱默简并性。相反，以一般方式以及说明性示例开发了辛类的修正非布洛赫能带理论。这种非标准非布洛赫能带理论是受互易性保护的 Z(2) 非厄米集肤效应的基础。
Non-Hermitian Hamiltonians are generally sensitive to boundary conditions, and their spectra and wave functions under open boundary conditions are not necessarily predicted by the Bloch band theory for periodic boundary conditions. To elucidate such a non-Bloch feature, recent works have developed a non-Bloch band theory that works even under arbitrary boundary conditions. Here, it is demonstrated that the standard non-Bloch band theory breaks down in the symplectic class, in which non-Hermitian Hamiltonians exhibit Kramers degeneracy because of reciprocity. Instead, a modified non-Bloch band theory for the symplectic class is developed in a general manner, as well as illustrative examples. This nonstandard non-Bloch band theory underlies the Z(2) non-Hermitian skin effect protected by reciprocity.