Spin-Valley Locking Effect in Defect States of Monolayer MoS${}_2$

Abstract

Valley pseudospin in two-dimensional (2D) transition-metal dichalcogenides (TMDs) allows optical control of spin-valley polarization and intervalley quantum coherence. Defect states in TMDs give rise to new exciton features and theoretically exhibit spin-valley polarization; however, experimental achievement of this phenomenon remains challenges. Here, we report unambiguous valley pseudospin of defect-bound localized excitons in CVD-grown monolayer MoS2; enhanced valley Zeeman splitting with an effective g-factor of -6.2 is observed. Our results reveal that all five d-orbitals and the increased effective electron mass contribute to the band shift of defect states, demonstrating a new physics of the magnetic responses of defect-bound localized excitons, strikingly different from that of A excitons. Our work paves the way for the manipulation of the spin-valley degrees of freedom through defects toward valleytronic devices.

References in corpus (7)

• Valley polarization in MoS2 monolayers by optical pumping
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• Magnetic Control of Valley Pseudospin in Monolayer WSe2
• Isolated electron spins in silicon carbide with millisecond-coherence times
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Cited by in corpus (2)

• Intrinsic Donor-Bound Excitons in Ultraclean Monolayer Semiconductors
• Symmetry breaking and spin-orbit coupling for individual vacancy-induced in-gap states in MoS2 monolayers