TY  - JOUR
AU  - Chen, Guan-Yu
AU  - Huang, Angus
AU  - Lin, Yen-Hui
AU  - Chen, Chia-Ju
AU  - Lin, Deng-Sung
AU  - Chang, Po-Yao
AU  - Jeng, Horng-Tay
AU  - Bihlmayer, Gustav
AU  - Hsu, Pin-Jui
TI  - Orbital-enhanced warping effect in px,py-derived Rashba spin splitting of monatomic bismuth surface alloy
JO  - npj quantum materials
VL  - 5
IS  - 1
SN  - 2397-4648
CY  - [London]
PB  - Nature Publishing Group
M1  - FZJ-2020-04931
SP  - 89
PY  - 2020
AB  - Spin-split Rashba bands have been exploited to efficiently control the spin degree of freedom of moving electrons, which possesses a great potential in frontier applications of designing spintronic devices and processing spin-based information. Given an intrinsic breaking of inversion symmetry and sizeable spin–orbit interaction, two-dimensional (2D) surface alloys formed by heavy metal elements exhibit a pronounced Rashba-type spin splitting of the surface states. Here, we have revealed the essential role of atomic orbital symmetry in the hexagonally warped Rashba spin-split surface state of the 3–√×3–√R300 BiCu2 monatomic alloy by scanning tunneling spectroscopy (STS) and density functional theory (DFT). From dI/dU spectra and calculated band structures, three hole-like Rashba-split bands hybridized from distinct orbital symmetries have been identified in the unoccupied energy region. Because of the hexagonally deformed Fermi surface, quasi-particle interference (QPI) mappings have resolved scattering channels opened from interband transitions of px,py (mj = 1/2) band. In contrast to the s,pz-derived band, the hexagonal warping is predominately accompanied by substantial out-of-plane spin polarization Sz up to 24% in the dispersion of px,py (mj = 1/2) band with an in-plane orbital symmetry.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000597293600002
DO  - DOI:10.1038/s41535-020-00293-3
UR  - https://juser.fz-juelich.de/record/888463
ER  -