论文标题
相互作用下的特殊点的命运：减少拓扑分类
Fate of exceptional points under interactions: Reduction of topological classifications
论文作者
论文摘要
尽管最近对非热拓扑的广泛研究，但理解相互作用效应仍然是一个至关重要的问题。在本文中，我们解决了对非平凡点间隙拓扑保护的特殊点的相互作用影响，而非平方宽度是非平地系统独有的。我们在二维参数空间中的分析阐明了异常点和对称性保护的异常环的存在，以易碎相互作用。它们仅在非相互作用的情况下受到拓扑保护。异常点和受对称性保护的异常环的这种脆弱性是由于降低了非铁质拓扑分类的原因，这是通过引入第二量化的汉密尔顿的拓扑不变性来阐明的，用于非相互作用和相互作用的情况。这些拓扑不变性也可用于分析间隙系统的还原现象。以上结果强烈表明，在通用病例中，异常点的相似现象类似，并在非富裕拓扑学中开辟了新的研究方向。
Despite recent extensive studies of the non-Hermitian topology, understanding interaction effects is left as a crucial question. In this paper, we address interaction effects on exceptional points which are protected by the non-trivial point-gap topology unique to non-Hermitian systems. Our analysis in a two-dimensional parameter space elucidates the existence of exceptional points and symmetry-protected exceptional rings fragile against interactions; they are topologically protected only in non-interacting cases. This fragility of exceptional points and symmetry-protected exceptional rings arises from the reduction of non-Hermitian topological classifications, which is elucidated by introducing topological invariants of the second-quantized Hamiltonian for both non-interacting and interacting cases. These topological invariants are also available to analyze the reduction phenomena of gapped systems. The above results strongly suggest similar reduction phenomena of exceptional points in generic cases and open up a new direction of research in the non-Hermitian topology.
