Robust valley coherence of excitons in MoS₂ (IMAGE)

Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, CAS

Robust valley coherence of excitons in MoS₂

Caption

a, Top Row – Schematic of the hBN-MoS₂-hBN (HMH) stack. Bottom Row (Left) – Linear polarization resolved photoluminescence (PL) spectrum of the HMH stack, showing ~37% degree of linear polarization (DOLP) of the A1s exciton peak. Bottom Row (Right) – Bloch Sphere schematic of the exciton pseudospin. Upon generation, the pseudospin lies in the equator and points in the direction as determined by the polarization axis of the excitation light. The direction of the pseudospin changes in a random manner, leading to loss in valley coherence, as suggested by low DOLP value in the PL measurement. b, Top Row – Schematic of the Graphene-MoS₂-Graphene (GMG) stack. Bottom Row (Left) - Linear Polarization resolved PL spectrum of the GMG stack, showing ~100% DOLP of the A1s exciton peak. Bottom Row (Right) – The pseudospin direction remains unperturbed after generation as all the excitons collected in the steady-state PL remain fully coherent, as reflected by observing 100% exciton DOLP in the PL measurement.

Credit

by Garima Gupta, Kenji Watanabe, Takashi Taniguchi, and Kausik Majumdar

Usage Restrictions

Credit must be given to the creator.

License

CC BY

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