Selection rules for Cooper pairing in two-dimensional interfaces and sheets

Abstract

Quantum physics: new rules for superconductivity behaviors Thin sheets represent an important materials source for the realization of exotic electronic states. A noteworthy example is the noncentrosymmetric two-dimensional (2D) superconductor whose broken inversion symmetry is known to have an impact on the superconducting behaviors, such as Cooper instabilities. Now Mathias S. Scheurer at Karlsruhe Institute of Technology in Germany and his colleagues from Germany and USA derive general selection rules for Cooper instabilities in such 2D systems by considering both symmetry and energetic factors. These rules are proved to have wider implications for various materials, such as thin layers of Sr2RuO4, URu2Si2 and UPt3, LaAlO3/SrTiO3 heterostructures, and single FeSe layer. Importantly, the principles could serve as a fundamental guideline in the search for superconductivity with missing time reversal symmetry (TRS) in the absence of external magnetic fields.