Unconventional steady states and topological phases in an open two-level non-Hermitian system

• URL: http://arxiv.org/abs/2004.03703v4
• Date: Sat, 28 May 2022 05:40:42 GMT
• Title: Unconventional steady states and topological phases in an open two-level non-Hermitian system
• Authors: Jian Xu and Youneng Guo
• Abstract summary: We study an open two-level non-Hermitian system coupling to a dissipative environment by solving the vectorized Lindblad equation. Our results show that there exist a new class of exceptional points (EPs) and steady states due to the interplay between non-Hermiticity and decoherence. It is revealed that the phases of eigenstates located in Fermi arcs regime have a topological phase $|pi/2|$ which is totally unaffected by the dissipative environment.
• Score: 3.2558897563787674
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Decoherence and non-Hermiticity are two different effects of the open quantum systems. Both of them have triggered many interesting phenomena. In this paper, we theoretically study an open two-level non-Hermitian system coupling to a dissipative environment by solving the vectorized Lindblad equation. This scheme provides us a powerful framework to address widespread open systems with gain, loss and dissipation. Our results show that there exist a new class of exceptional points (EPs) and steady states due to the interplay between non-Hermiticity and decoherence. Furthermore, we also demonstrate new-type topological properties of eigenstates with zero real-part of eigenvalues ($Re[\lambda]=0$) which are corresponding to Fermi arcs. It is revealed that the phases of eigenstates located in Fermi arcs regime have a topological phase $|\pi/2|$ which is totally unaffected by the dissipative environment. Our results provide a promising approach for further uncovering and understanding the intriguing properties of non-Hermitian open systems.

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