TY - JOUR
T1 - Temperature-driven evolution of critical points, interlayer coupling, and layer polarization in bilayer Mo S2
AU - Du, Luojun
AU - Zhang, Tingting
AU - Liao, Mengzhou
AU - Liu, Guibin
AU - Wang, Shuopei
AU - He, Rui
AU - Ye, Zhipeng
AU - Yu, Hua
AU - Yang, Rong
AU - Shi, Dongxia
AU - Yao, Yugui
AU - Zhang, Guangyu
N1 - Funding Information:
We acknowledge Feng Wang from University of California, Berkeley and Marek Potemski from Laboratoire National des Champs Magnétiques Intenses for valuable discussions. G.Y.Z. thanks the National Key R&D program under Grant No. 2016YFA0300904, the National Science Foundation of China (NSFC, Grant No. 61325021), the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences (CAS, Grant No. QYZDB-SSW-SLH004), and the Strategic Priority Research Program (B) of CAS (Grants No. XDPB0602 and No. XDB07010100) for support. D.X.S. thanks the NSFC for support with Grant No. 51572289. R.Y. acknowledges the support of the National 973 program (Grant No. 2013CBA01602) and the NSFC with the Grant No. 11574361. R.H. acknowledges support by the CAREER Grant from the United States NSF (Grant No. DMR-1760668).
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/4/9
Y1 - 2018/4/9
N2 - The recently emerging two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have been a fertile ground for exploring abundant exotic physical properties. Critical points, the extrema or saddle points of electronic bands, are the cornerstone of condensed-matter physics and fundamentally determine the optical and transport phenomena of the TMDCs. However, for bilayer MoS2, a typical TMDC and the unprecedented electrically tunable venue for valleytronics, there has been a considerable controversy on its intrinsic electronic structure, especially for the conduction band-edge locations. Moreover, interlayer hopping and layer polarization in bilayer MoS2 which play vital roles in valley-spintronic applications have remained experimentally elusive. Here, we report the experimental observation of intrinsic critical points locations, interlayer hopping, layer-spin polarization, and their evolution with temperature in bilayer MoS2 by performing temperature-dependent photoluminescence. Our measurements confirm that the conduction-band minimum locates at the Kc instead of Qc, and the energy splitting between Qc and Kc redshifts with a descent of temperature. Furthermore, the interlayer hopping energy for holes and temperature-dependent layer polarization are quantitatively determined. Our observations are in good harmony with density-functional theory calculations.
AB - The recently emerging two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have been a fertile ground for exploring abundant exotic physical properties. Critical points, the extrema or saddle points of electronic bands, are the cornerstone of condensed-matter physics and fundamentally determine the optical and transport phenomena of the TMDCs. However, for bilayer MoS2, a typical TMDC and the unprecedented electrically tunable venue for valleytronics, there has been a considerable controversy on its intrinsic electronic structure, especially for the conduction band-edge locations. Moreover, interlayer hopping and layer polarization in bilayer MoS2 which play vital roles in valley-spintronic applications have remained experimentally elusive. Here, we report the experimental observation of intrinsic critical points locations, interlayer hopping, layer-spin polarization, and their evolution with temperature in bilayer MoS2 by performing temperature-dependent photoluminescence. Our measurements confirm that the conduction-band minimum locates at the Kc instead of Qc, and the energy splitting between Qc and Kc redshifts with a descent of temperature. Furthermore, the interlayer hopping energy for holes and temperature-dependent layer polarization are quantitatively determined. Our observations are in good harmony with density-functional theory calculations.
UR - http://www.scopus.com/inward/record.url?scp=85045181675&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.97.165410
DO - 10.1103/PhysRevB.97.165410
M3 - Article
AN - SCOPUS:85045181675
VL - 97
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 16
M1 - 165410
ER -