Regular Article - Solid State and Materials
Topological defect states and phase transitions in mesoscopic superconducting squares with Rashba spin–orbit interaction
Department of Physics and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, 200444, Shanghai, China
Accepted: 18 June 2022
Published online: 28 June 2022
Based on the spin-generalized Bogoliubov–de Gennes theory, we investigate the topological defect configurations in a mesoscopic superconducting square with spin–orbit (SO) interaction. The mixed even-parity d-wave and extended s-wave components can be obtained by suitable choice of the chemical potential in such a system. We find that several novel types of topological defect states can be generated in the presence of Rashba SO coupling when the external magnetic flux turns on. Unclosed domain-wall states carrying even or odd number of one-component vortices as well as double-quanta skyrmionic patterns can appear for different Rashba SO-coupling strengths. The next-nearest-neighbor hopping effect on the evolution of topological structures is further examined. A skyrmionic chain feature with one-component vortex–antivortex pairs can show up in the present mixed-pairing system. Our investigation may provide useful information for future experiments and shed new light on device designing.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2022