| Summary: | 碩士 === 國立臺灣大學 === 物理學研究所 === 104 === Bismuth Tellurohalides are semiconductors with a giant Rashba e ect. They have two oppositely polarised surfaces with two-dimensional spin-momentum locked he- lical charge carriers, which are good candidates to achieve the goal of spin control in novel spintronic devices. Within the framework of density functional theory, we study the band structure of the Te-termination of ordered phase bismuth telluro- bromide, BiTeBr. Considering all the possible parings of initial and nal states in the constant energy contours (CEC), we further simulate the quasiparticle interfer- ence (QPI) patterns. By excluding or including the helical spin texture, there are actually two versions of simulated QPI patterns, joint density of states (JDOS) and spin scattering probability (SSP). Finally, we compare the simulated phenomena with measured tunnelling spectro-microscopy maps. We show that backscattering with opposite spin is absent in this system.
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