Quantitative Measurement of Temperature-Dependent Quasiparticle Scattering of the Topological Surface States in Bi₂Se₃

The quasiparticle scattering processes of the topological surface state (TSS) in three-dimensional topological insulators (TIs) have a vital effect on the many-body interactions and potential applications of topological materials. In this study, we performed high-resolution temperature-dependent angle-resolved photoemission spectroscopy analysis of the 3D strong TI Bi₂Se₃. Using an ab initia simulation, we analyzed the temperature dependence of the electronic structure and lifetime broadening of the TSS, which are closely associated with the quasiparticle scattering process, i.e., electron-phonon coupling and spin-dependent scattering. We show that, at a low temperature (7 K), the spin-dependent electron scattering facilitates the anisotropic scattering rate of the TSS. Conversely, at room temperature (300 K), the electron-phonon coupling dominates the contribution to the scattering rate. The scattering rate increases with temperature and becomes uniform in momentum space owing to the temperature dependence of quasiparticle scattering. The quantitative study of temperature-dependent scattering rates in TSS is crucial to understanding the topological property and transport mobility of Dirac fermions for fundamental studies and potential applications.