论文标题
观察非平价时间对称性和特殊点
Observation of non-Bloch parity-time symmetry and exceptional points
论文作者
论文摘要
平价时间（PT） - 对称性汉密尔顿人在非热物理学中具有广泛的意义。 PT对称的哈密顿量可以表现出具有真实或复杂特征的不同阶段，而在所谓的特殊点之间的过渡点会引起许多关键行为，这些行为对应用具有巨大的希望。对于在空间周期性的非热系统中，PT对称性通常是根据Bloch带理论一致的，并且在布里群区域内居住着特殊的点。在这里，在单一光子的单一量子步行中，我们发现了一个超出这种共同智慧的新颖家族。这些“非布洛克特殊点”源自边界附近的散装本征的积累，被称为非铁皮皮肤效应，并居住在一个广义的布里群区域。我们的发现为通用的PT对称框架开辟了道路，并揭示了PT对称性和非富甲皮肤效应之间的有趣相互作用。
Parity-time (PT)-symmetric Hamiltonians have widespread significance in non-Hermitian physics. A PT-symmetric Hamiltonian can exhibit distinct phases with either real or complex eigenspectrum, while the transition points in between, the so-called exceptional points, give rise to a host of critical behaviors that holds great promise for applications. For spatially periodic non-Hermitian systems, PT symmetries are commonly characterized and observed in line with the Bloch band theory, with exceptional points dwelling in the Brillouin zone. Here, in nonunitary quantum walks of single photons, we uncover a novel family of exceptional points beyond this common wisdom. These "non-Bloch exceptional points" originate from the accumulation of bulk eigenstates near boundaries, known as the non-Hermitian skin effect, and inhabit a generalized Brillouin zone. Our finding opens the avenue toward a generalized PT-symmetry framework, and reveals the intriguing interplay between PT symmetry and non-Hermitian skin effect.
