Odd–Parity Spin–Triplet Superconductivity in Centrosymmetric Antiferromagnetic Metals

We propose a route to achieve odd-parity spin-triplet superconductivity in metallic collinear antiferromagnets with inversion symmetry. Owing to the existence of hidden antiunitary symmetry, which we call the effective time-reversal symmetry (eTRS), the Fermi surfaces of ordinary antiferromagnetic metals are generally spin-degenerate, and spin-singlet pairing is favored. However, by introducing a perturbation that breaks the eTRS, we can lift the degeneracy to obtain spin-polarized Fermi surfaces. In the weak-coupling limit, the spin-polarized Fermi surfaces constrain the electrons to form spin-triplet Cooper pairs with odd-parity. Interestingly, all the odd-parity superconducting ground states we obtained host nontrivial band topologies. We propose that double perovskites with collinear antiferromagnetic or ferrimagnetic ordering, such as SrLaVMoO6, are promising candidate systems where our theoretical ideas can be applied to.