2023/09/01 by Jinying Wang, Wang, Jinying, Gerhard Klimeck +1
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Magnetic and transport properties of perovskites and related materials #Materials Science (cond-mat.mtrl-sci) #Rare-earth and actinide compounds #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2309.00469
openalex publication_date 2023/09/01 · openalex created_date 2023/09/05 · openalex updated_date 2026/07/28
A topological transition in high-temperature superconductors FeTe1-xSex, occurring at a critical range of Se concentration x, underlies their intrinsic topological superconductivity and emergence of Majorana states within vortices. Nonetheless, the influence of Se concentration and distribution on the electronic states in FeTe1-xSex remains unclear, particularly concerning their relationship with the presence or absence of Majorana states. In this study, we combine density functional theory (DFT) calculations, pz-dxz/yz-based and Wannier-based Hamiltonian analysis to systematically explore the electronic structures of diverse FeTe1-xSex compositions. Our investigation reveals a nonlinear variation of the spin-orbit coupling (SOC) gap between pz and dxz/yz bands in response to x, with the maximum gap occurring at x = 0.5. The pz-pz and dx2-y2-pz interactions are found to be critical for pd band inversion. Furthermore, we ascertain that the distribution of Se significantly modulates the SOC gap, thereby influencing the presence or absence of Majorana states within local vortices.