2018 workshop on Quantum Information Science: Are we at the crossroads?
Michigan State University, East Lansing, Michigan, September 30 - October 3, 2018.

Single Quantum Emitters for
Encrypted Satellite Communication:
Which Defects in WSe2 Can Do It?

Shuyue Xue, Andrii Kyrylchuk, Dan Liu, and David Tománek
Department of Physics and Astronomy, Michigan State University, USA
E-mail: tomanek@pa.msu.edu

Monolayers of transition metal dichalcogenides (TMDs) including MoS2 and WSe2 have received wide scientific attention as 2D semiconductors with a direct fundamental gap and potential application in optoelectronics. Recent identification of single-photon emission from excitons pinned by defects in WSe2 [1] can be seen as a milestone in photonic quantum-information technology enabling encrypted satellite communication and quantum teleportation [2]. The defects associated with intense narrow spectral lines in the emission spectrum, which enable single-photon emission, have not been identified yet. Such identification can be accomplished by combining core-level photoemission spectroscopy with quantitative calculations of core-level spectra. This approach has been successfully used to identify the nature and distribution of defects in samples of exfoliated black phosphorus [3].

[1] Yu-Ming He, Genevieve Clark, John R. Schaibley, Yu He, Ming-Cheng Chen, Yu-Jia Wei, Xing Ding, Qiang Zhang, Wang Yao, Xiaodong Xu, Chao-Yang Lu, and Jian-Wei Pan, "Single quantum emitters in monolayer semiconductors", Nature Nanotechnology 10, 497-502 (2015).
[2] Ji-Gang Ren et al., "Ground-to-satellite quantum teleportation", Nature 549, 70-73 (2017).
[3] Teng Yang, Baojuan Dong, Jizhang Wang, Zhidong Zhang, Jie Guan, Kaci Kuntz, Scott C. Warren, and David Tománek, "Interpreting core-level spectra of oxidizing phosphorene: theory and experiment", Phys. Rev. B 92, 125412 (2015).