Coupled spin and valley physics in monolayer MoS2 and group-VI dichalcogenides

Journal Article · Sun Jan 01 04:00:00 EST 2012 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.108.196802· OSTI ID:1039619

Xiao, Di ^[1]; Liu, G. B. ^[2]; Feng, wanxiang ^[3]; Xu, Xiaodong ^[4]; Yao, Wang ^[2]

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1. ORNL
2. University of Hong Kong, The
3. Chinese Academy of Sciences
4. University of Washington

We show that inversion symmetry breaking together with spin-orbit coupling leads to coupled spin and valley physics in monolayer MoS2 and group-VI dichalcogenides, making possible controls of spin and valley in these 2D materials. The spin-valley coupling at the valence band edges suppresses spin and valley relaxation, as flip of each index alone is forbidden by the 0.1 eV valley contrasting spin splitting. Valley Hall and spin Hall effects coexist in both electron-doped and hole-doped systems. Optical interband transitions have frequency-dependent polarization selection rules which allow selective photoexcitation of carriers with various combination of valley and spin indices. Photo-induced spin Hall and valley Hall effects can generate long lived spin and valley accumulations on sample boundaries. The physics discussed here provides a route towards the integration of valleytronics and spintronics in multi-valley materials with strong spin-orbit coupling and inversion symmetry breaking.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1039619
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 19 Vol. 108; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
HALL EFFECT
PHYSICS
POLARIZATION
RELAXATION
SELECTION RULES
SPIN
SYMMETRY BREAKING
VALENCE