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Atomically thin materials with honeycomb lattice have intriguing opto-electronic properties due to strong
carrier interactions and the presence of additional electronic degree of freedoms such as the valley
pseudospin. Recently, single photon emitters (SPE) in atomically thin transition metal dichalcogenides
such as WSe2 have been reported which, possibly arise from excitons trapped in shallow potentials. We
perform low-temperature magneto-optical spectroscopy on WSe2 quantum dots (QD) in field effect
transistor geometry. Correlations of spectral wandering allows us to assign multiple peaks arising from the
same QD. We observe entanglement of neutral SPE with in-plane chiral phonon modes of WSe2. This
results in unpolarized single photon emission, with the polarization recovered in an out-of-plane magnetic
field. In addition, we find evidence for singly charged quantum dots with an excess spin. We demonstrate
optical initialization of single spin with the helicity of incident light. Our findings open up ways for
valleytronic based quantum optics in 2D materials . |