Abstract
We report characteristic vortex configurations in superconductors with time-reversal symmetry breaking, exposed to magnetic field. A vortex in the state tends to have an opposite phase winding between - and condensates. We find that this peculiar feature together with the competition between - and symmetry results in three distinct classes of vortical configurations. When either or condensate absolutely dominates, vortices form a conventional lattice. However, when one condensate is relatively dominant, vortices organize in chains that exhibit skyrmionic character, separating the chiral components of the order parameter into domains within and outside the chain. Such skyrmionic chains are found stable even at high magnetic field. When and condensates have comparable strength, vortices split cores in two chiral components to form full-fledged skyrmions, i.e., coreless topological structures with an integer topological charge, organized in a lattice. We provide characteristic magnetic field distributions of all states, enabling their identification in, e.g., scanning Hall probe and scanning SQUID experiments. These unique vortex states are relevant for high- cuprate and iron-based superconductors, where the relative strength of competing pairing symmetries is expected to be tuned by temperature and/or doping level, and can help distinguish and superconducting phases.
- Received 4 October 2019
- Revised 22 January 2020
- Accepted 23 January 2020
DOI:https://doi.org/10.1103/PhysRevB.101.064501
©2020 American Physical Society