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arXiv · 2004.03703

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

Jian Xu·Youneng Guo
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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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Jian Xu, Youneng Guo. 2020-04-07. Unconventional steady states and topological phases in an open two-level non-Hermitian system. https://doi.org/10.1088/1367-2630/ac69b2

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