Superconductivity in the antiperovskite Dirac-metal oxide Sr3−xSnO

Abstract

Investigations of perovskite oxides triggered by the discovery of high-temperature and unconventional superconductors have had crucial roles in stimulating and guiding the development of modern condensed-matter physics. Antiperovskite oxides are charge-inverted counterpart materials to perovskite oxides, with unusual negative ionic states of a constituent metal. No superconductivity was reported among the antiperovskite oxides so far. Here we present the first superconducting antiperovskite oxide Sr3−xSnO with the transition temperature of around 5 K. Sr3SnO possesses Dirac points in its electronic structure, and we propose from theoretical analysis a possibility of a topological odd-parity superconductivity analogous to the superfluid 3He-B in moderately hole-doped Sr3−xSnO. We envision that this discovery of a new class of oxide superconductors will lead to a rapid progress in physics and chemistry of antiperovskite oxides consisting of unusual metallic anions.

Evolution of band topology by competing band overlap and spin-orbit coupling: Twin Dirac cones in Ba3SnO as a prototype

“…It is also worth noting that experiments on this series of materials are now developing. We have highly refined crystal characterization [28], thin film fabrication [29,30], a thermal measurement [31], and even a report of superconductivity [32].In this paper, we show that the competition between SOC and the band overlap leads to an interesting evolution of the band structure, taking Ba 3 SnO as a prototypical example. In the previous work on the analysis of the antiperovskite family [24], we regarded that the SOC arXiv:1705.08934v1 [cond-mat.mes-hall]…”

“…It is also worth noting that experiments on this series of materials are now developing. We have highly refined crystal characterization [28], thin film fabrication [29,30], a thermal measurement [31], and even a report of superconductivity [32].…”

The role of intrinsic vacancy defects in the electronic and magnetic properties of Sr3SnO: a first-principles study

“…12 To elaborate on the bonding properties of pristine and intrinsic vacancy containing supercells of SSO we have computed the effective Bader charges (e) of Sn, O and Sr as well as the electronic charge density plots. 31 In case of bulk SSO, the effective Bader charges of Sn, O and Sr are found to be À2.330 e, À1.512 e and 1.282 e, respectively.…”

“…8,[11][12][13] Klintenberg et al performed density functional theory (DFT) based comprehensive computational data-mining of several materials to reveal the topological behavior of narrow band gap SSO.…”

“…40 Since electronic band structure of inverse perovskites are very sensitive to lattice parameters, we suspect that the choice of lattice parameter and/or the energy cut-off for the FP-LAPW may be responsible for the electronic band structure of SSO presented in ref. 12. For a further conrmation of bulk TI phase of SSO, we have computed the inversion energy, 40 which is found to be À0.435 eV.…”