Symmetry aspects of chiral superconductors

Abstract

Recent developments in theory, synthesis, and experimental probes of quantum systems have revealed many suitable candidate materials to host chiral superconductivity. Chiral superconductors are a subset of unconventional superconductors which break time-reversal symmetry. Time-reversal symmetry breaking is possible given the order parameter's two-component nature, allowing for a complex relative phase. In this article, we focus on discussing the underlying symmetry aspects that allow for the development of chiral superconductivity. We provide an introductory account of key concepts in group theory and apply these to the classification of order parameters and the generalization of the Landau theory of phase transitions in the context of superconductivity.

Keywords:

• Chiral superconductors
• unconventional superconductors
• group theory
• irreducible representations
• Landau theory

Acknowledgments

The author thanks Manfred Sigrist for discussions.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

The author is supported by the Swiss National Science Foundation through the Ambizione Grant No. 186043.

Notes on contributors

Aline Ramires

Aline Ramires is an Ambizione Fellow in the Condensed Matter Theory group at the Paul Scherrer Insitute, Switzerland. She obtained her Ph.D. in 2015 at Rutgers University, USA. After that, Aline Ramires was an ITS Fellow at ETH Zurich in Switzerland and held positions in the MPI-PKS in Germany and the ICTP-SAIFR in Brazil. She is interested in the phenomenology of unconventional superconductors and strongly correlated electron systems. She proposed the concept of superconducting fitness, a handy framework for understanding the unconventional properties of unconventional superconductors. She received the Nevill F. Mott Prize in 2022.