Competition between electron-phonon coupling and spin fluctuations in superconducting hole-doped CuBiSO

Abstract

BiOCuS is a band insulator that becomes metallic upon hole doping. Superconductivity was recently reported in doped BiOCu1−xS and attributed to spin fluctuations as a pairing mechanism. Based on first principles calculations of the electron-phonon coupling, we argue that the latter is very strong in this material, and probably drives superconductivity, which is however strongly depressed by the proximity to magnetism. We find however that BiOCu1−xS is a quite unique compound where both a conventional phonon-driven and an unconventional triplet superconductivity are possible, and compete with each other. We argue that, in this material, it should be possible to switch from conventional to unconventional superconductivity by varying such parameters as doping or pressure.

Theoretical investigation of superconductivity inSrPd2Ge2,SrPd2As2, andKaraca1, Tütüncü2, Uzunok3 et al. 2016Phys. Rev. B

“…Previous ab initio works have reported much higher values of T c than the corresponding experimental measurements. These include the work by Subedi and Singh [18] on BaNi 2 As 2 , the work by Ortenzi et al [33] on CuBiSO, and the work by Subedi [34] on K 2 Cr 3 As 3 . As noted in Table III that there are four estimates of T c from experimental studies on SrPd 2 Ge 2 in Refs.…”

Prediction of Superconductivity in 3d Transition-Metal Based Antiperovskites via Magnetic Phase Diagram

“…The effective mass of the carriers should be enhanced by the factor 1 + λ Z = 1 + λ + λ sf . And equation (4) shound be changed as 53,57 …”

Strong-coupling electron-phonon superconductivity in noncentrosymmetric quasi-one-dimensionalK2Cr3As3

“…Another reason for the overestimation might be because I have neglected the effects of magnetic fluctuations. First principles calculations show the presence of various magnetic interactions within this material [14,15], and this will also suppress T c [28].…”