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arXiv · 1101.4656

Identifying spin-triplet pairing in spin-orbit coupled multi-band superconductors

Abstract

We investigate the combined effect of Hund's and spin-orbit (SO) coupling on superconductivity in multi-orbital systems. Hund's interaction leads to orbital-singlet spin-triplet superconductivity, where the Cooper pair wave function is antisymmetric under the exchange of two orbitals. We identify three d-vectors describing even-parity orbital-singlet spin-triplet pairings among t2g-orbitals, and find that the three d-vectors are mutually orthogonal to each other. SO coupling further assists pair formation, pins the orientation of the d-vector triad, and induces spin-singlet pairings with a relative phase difference of π/2. In the band basis the pseudospin d-vectors are aligned along the z-axis and correspond to momentum-dependent inter- and intra-band pairings. We discuss quasiparticle dispersion, magnetic response, collective modes, and experimental consequences in light of the superconductor Sr2RuO4.

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Christoph M. Puetter, Hae-Young Kee. 2012-05-03. Identifying spin-triplet pairing in spin-orbit coupled multi-band superconductors. https://doi.org/10.1209/0295-5075%2F98%2F27010

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