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arXiv · 1710.05546

Photoinduced topological phase transitions in strained black phosphorus

Hang Liu·Jia-Tao Sun·Cai Cheng·Feng Liu·Sheng Meng
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Abstract

Photoinduced topological phase transitions (TPTs) in black phosphorous (BP) under compressive strain were investigated by combining Floquet theory and first-principles calculations. Intriguing photo-dressed electronic states including Floquet-Dirac semimetals and Floquet topological insulators have been identified, which can be feasibly engineered by changing the direction, intensity and frequency of incident laser. Remarkably, tunable TPT from type-I to type-II Floquet-Dirac fermions can be realized by irradiating circularly polarized laser (CPL), with an origin rooted in optical Stark effect. Furthermore, the photoinduced Floquet-Dirac phases is shown to host topological surface states that exhibit nonequilibrium electron transport in a direction locked by the helicity of CPL. This work provides useful guidance for experimental observation of Floquet TPTs, and extends optoelectrionic applications of BP to nonequilibrium regime.

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Hang Liu, Jia-Tao Sun, Cai Cheng, Feng Liu, Sheng Meng. 2017-10-16. Photoinduced topological phase transitions in strained black phosphorus. https://doi.org/10.1103/physrevlett.120.237403

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