2020/06/09 by Guanyu Chen, Chen, Guan-Yu, Angus Huang +15
Physics and Astronomy · #FOS: Physical sciences #Magnetic properties of thin films #Materials Science (cond-mat.mtrl-sci) #Quantum and electron transport phenomena #Surface and Thin Film Phenomena
paper · pdf · doi:10.48550/arxiv.2006.05024
openalex publication_date 2020/06/09 · openalex created_date 2020/06/19 · openalex updated_date 2026/07/28
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 that 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 √(3)×√(3) R30∘ 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 \textitpx,py(mj=1/2) band. In contrast to the \textits,pz-derived band, the hexagonal warping predominately is accompanied by substantial out-of-plane spin polarization Sz up to 24% in the dispersion of \textitpx,py(mj=1/2) band with an in-plane orbital symmetry.