| Autor: |
Rømer AT; Niels Bohr Institute, University of Copenhagen, Vibenhuset, Lyngbyvej 2, DK-2100 Copenhagen, Denmark.; Institut Laue-Langevin, 71 avenue des Martyrs CS 20156, 38042 Grenoble Cedex 9, France., Scherer DD; Niels Bohr Institute, University of Copenhagen, Vibenhuset, Lyngbyvej 2, DK-2100 Copenhagen, Denmark., Eremin IM; Institut für Theoretische Physik III, Ruhr-Universität Bochum, D-44801 Bochum, Germany.; National University of Science and Technology MISiS, 119049 Moscow, Russia., Hirschfeld PJ; Department of Physics, University of Florida, Gainesville, Florida 32611, USA., Andersen BM; Niels Bohr Institute, University of Copenhagen, Vibenhuset, Lyngbyvej 2, DK-2100 Copenhagen, Denmark. |
| Abstrakt: |
Recent nuclear magnetic resonance studies [A. Pustogow et al., Nature 574, 72 (2019)] have challenged the prevalent chiral triplet pairing scenario proposed for Sr_{2}RuO_{4}. To provide guidance from microscopic theory as to which other pair states might be compatible with the new data, we perform a detailed theoretical study of spin fluctuation mediated pairing for this compound. We map out the phase diagram as a function of spin-orbit coupling, interaction parameters, and band structure properties over physically reasonable ranges, comparing when possible with photoemission and inelastic neutron scattering data information. We find that even-parity pseudospin singlet solutions dominate large regions of the phase diagram, but in certain regimes spin-orbit coupling favors a near-nodal odd-parity triplet superconducting state, which is either helical or chiral depending on the proximity of the γ band to the van Hove points. A surprising near degeneracy of the nodal s^{'} and d_{x^{2}-y^{2}} wave solutions leads to the possibility of a near-nodal time-reversal symmetry broken s^{'}+id_{x^{2}-y^{2}} pair state. Predictions for the temperature dependence of the Knight shift for fields in and out of plane are presented for all states. |
