title: Spin-orbit coupling enhanced superconductivity in Bi-rich compounds ABi₃ (A = Sr and Ba).
abstract: Recently, Bi-based compounds have attracted attentions because of the strong spin-orbit coupling (SOC). In this work, we figured out the role of SOC in ABi3 (A = Sr and Ba) by theoretical investigation of the band structures, phonon properties, and electron-phonon coupling. Without SOC, strong Fermi surface nesting leads to phonon instabilities in ABi3. SOC suppresses the nesting and stabilizes the structure. Moreover, without SOC the calculation largely underestimates the superconducting transition temperatures (Tc), while with SOC the calculated Tc are very close to those determined by measurements on single crystal samples. The SOC enhanced superconductivity in ABi3 is due to not only the SOC induced phonon softening, but also the SOC related increase of electron-phonon coupling matrix elements. ABi3 can be potential platforms to construct heterostructure of superconductor/topological insulator to realize topological superconductivity.
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: D F
authors.initials: DF
authors.lastname: Shao
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: X
authors.initials: X
authors.lastname: Luo
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: W J
authors.initials: WJ
authors.lastname: Lu
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: L
authors.initials: L
authors.lastname: Hu
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: X D
authors.initials: XD
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: W H
authors.initials: WH
authors.lastname: Song
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: X B
authors.initials: XB
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.|High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.|Collaborative Innovation Center of Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Y P
authors.initials: YP
authors.lastname: Sun