Robustness against non-magnetic impurities in topological superconductors

27th International Conference on Low Temperature Physics

Nagai, Y.^1 ; Ota, Y.^1 ; Machida, M.^1

CCSE, Japan Atomic Energy Agency, 5-1-5 Kashiwanoha, Chiba, Kashiwa

277-8587, Japan^1

关键词: Effective Hamiltonian;    First-principles calculation;    Impurity concentration;    Non-magnetic impurities;    Nonrelativistic limits;    P-Wave superconductivity;    Relativistic effects;    Zero-energy density of state;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/568/2/022030/pdf
DOI  :  10.1088/1742-6596/568/2/022030

来源: IOP

【 摘 要 】

We study The robustness against non-magnetic impurities in a three-dimensional topological superconductor, focusing on an effective model (massive Dirac Bogoliubov-de Gennes (BdG) Hamiltonian with s-wave on-site pairing) of CuxBi2Se3with The parameter set determined by The first-principles calculation. With The use of The self-consistent T- matrix approximation for impurity scattering, we discuss The impurity-concentration dependence of The zero-energy density of states. We show that a single material variable, measuring relativistic effects in The Dirac-BdG Hamiltonian, well characterizes The numerical results. In The nonrelativistic limit, The odd-parity fully-gapped topological superconductivity is fragile against non-magnetic impurities, since this superconductivity can be mapped onto The p-wave superconductivity. On The other hand, in The ultrarelativistic limit, The superconductivity is robust against The non-magnetic impurities, since The effective model has The s-wave superconductivity. We derive The effective Hamiltonian in The both limit.