Emergence of electron coherence and two-color all-optical switching in MoS₂ based on spatial self-phase modulation

Generating electron coherence in quantum materials is essential in optimal control of many-body interactions and correlations. In a multidomain system this signifies nonlocal coherence and emergence of collective phenomena, particularly in layered 2D quantum materials possessing novel electronic str...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2015-09, Vol.112 (38), p.11800-11805
Main Authors: Wu, Yanling, Wu, Qiong, Sun, Fei, Cheng, Cai, Meng, Sheng, Zhao, Jimin
Format: Article
Language:English
Subjects:
Physical Sciences
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Summary:Generating electron coherence in quantum materials is essential in optimal control of many-body interactions and correlations. In a multidomain system this signifies nonlocal coherence and emergence of collective phenomena, particularly in layered 2D quantum materials possessing novel electronic structures and high carrier mobilities. Here we report nonlocal ac electron coherence induced in dispersed MoS₂ flake domains, using coherent spatial self-phase modulation (SSPM). The gap-dependent nonlinear dielectric susceptibilityχ (3)measured is surprisingly large, where direct interband transition and two-photon SSPM are responsible for excitations above and below the bandgap, respectively. A wind-chime model is proposed to account for the emergence of the ac electron coherence. Furthermore, all-optical switching is achieved based on SSPM, especially with two-color intraband coherence, demonstrating that electron coherence generation is a ubiquitous property of layered quantum materials.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.1504920112