Hidden spin polarization in the 1T-phase layered transition-metal dichalcogenides MX_2(M = Zr, Hf; X = S, Se, Te)  

作　　者：Cai Cheng Jia-Tao Sun Xiang-Rong Chen Sheng Meng 

机构地区：[1]Institute of Atomic and Molecular Physics, College of Physical Science and Technology, Sichuan University [2]Institute of Physics, Chinese Academy of Sciences

出　　处：《Science Bulletin》2018年第2期85-91,共7页科学通报（英文版）

基　　金：financially supported by the National Basic Research Program of China (2015CB921001, 2013CBA01600, and 2016YFA0300902);the National Natural Science Foundation of China (61306114);‘‘Strategic Priority Research Program (B)" of Chinese Academy of Sciences (XDB07030100);the National Natural Science Foundation of China Academy of Engineering Physics (U1430117);the Science Challenge Project (TZ2016001)

摘　　要：The recent discovery of hidden spin polarization emerging in layered materials of specific nonmagnetic crystal is a fascinating phenomenon, though hardly explored yet. Here, we have studied hidden spin tex- tures in layered nonmagnetic 1 T-phase transition-metal dichalcogenides MX2 （M = Zr, Hf; X = S, Se, Te） by using first-principles calculations. Spin-layer locking effect, namely, energy-degenerate opposite spins spatially separated in the top and bottom layer respectively, has been identified. In particular, the hidden spin polarization of 13-band can be easily probed, which is strongly affected by the strength of spin-orbit coupling. The hidden spin polarization of k-band locating at high symmetry M point （conduction band minimum） has a strong anisotropy. In the bilayer, the hidden spin polarization is preserved at the upmost Se layer, while being suppressed if the ZrSe2 layer is taken as the symmetry partner. Our results on hidden spin polarization in 1 T-phase dichalcogenides, verifiable by spin-resolved and angle-resolved photoemis- sion spectroscopy （ARPES）, enrich our understanding of spin physics and provide important clues to search for specific spin polarization in two dimensional materials for spintronic and quantum informa- tion applications.The recent discovery of hidden spin polarization emerging in layered materials of specific nonmagnetic crystal is a fascinating phenomenon, though hardly explored yet. Here, we have studied hidden spin textures in layered nonmagnetic 1 T-phase transition-metal dichalcogenides MX_2(M = Zr, Hf; X = S, Se, Te) by using first-principles calculations. Spin-layer locking effect, namely, energy-degenerate opposite spins spatially separated in the top and bottom layer respectively, has been identified. In particular, the hidden spin polarization of b-band can be easily probed, which is strongly affected by the strength of spin–orbit coupling. The hidden spin polarization of ξ-band locating at high symmetry M point(conduction band minimum) has a strong anisotropy. In the bilayer, the hidden spin polarization is preserved at the upmost Se layer, while being suppressed if the Zr Se_2 layer is taken as the symmetry partner. Our results on hidden spin polarization in 1 T-phase dichalcogenides, verifiable by spin-resolved and angle-resolved photoemission spectroscopy(ARPES), enrich our understanding of spin physics and provide important clues to search for specific spin polarization in two dimensional materials for spintronic and quantum information applications.

关 键 词：Hidden spin polarizationTransition-metal dichalcogenides 1T-phaseHelical spin textureCentrosymmetric 

分 类 号：O611.3[理学—无机化学]