Even odder after twenty-three years: the superconducting order parameter puzzle of Sr2RuO4

Abstract

In this short review, we aim to provide a topical update on the status of efforts to understand the superconductivity of Sr2RuO4. We concentrate on the quest to identify a superconducting order parameter symmetry that is compatible with all the major pieces of experimental knowledge of the material, and highlight some major discrepancies that have become even clearer in recent years. As the pun in the title suggests, we have tried to start the discussion from scratch, making no assumptions even about fundamental issues such as the parity of the superconducting state. We conclude that no consensus is currently achievable in Sr2RuO4, and that the reasons for this go to the heart of how well some of the key probes of unconventional superconductivity are really understood. This is therefore a puzzle that merits continued in-depth study.

References in corpus (8)

• Chiral P-Wave Order in Sr_2RuO_4
• Observation of half-height magnetization steps in Sr2RuO4
• Strong spin-orbit coupling effects on the Fermi surface of Sr2RuO4 and Sr2RhO4
• Hidden quasi one-dimensional superconductivity in Sr${}_2$RuO${}_4$
• Vanishing edge currents in non-$p$-wave topological chiral superconductors
• Non-topological nature of the edge current in a chiral p-wave superconductor
• Suppression of spontaneous currents in Sr${}_2$RuO${}_4$ by surface disorder
• Charge and spin collective modes in a quasi-1D model of Sr2RuO4

Cited by in corpus (2)

• Anisotropy and multiband superconductivity in Sr2RuO4
• Interband interference effects at the edge of a multiband chiral p-wave superconductor