Skyrmionic chains and lattices in $s+id$ superconductors

Abstract

We report characteristic vortex configurations in $s+id$ superconductors with time reversal symmetry breaking, exposed to magnetic field. A vortex in the $s+id$ state tends to have an opposite phase winding between $s-$ and $d-$wave condensates. We find that this peculiar feature together with the competition between $s-$ and $d-$wave symmetry results in three distinct classes of vortical configurations. When either $s-$ or $d-$ 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 $s\pm id$ order parameter into domains within and outside the chain. Such skyrmionic chains are found stable even at high magnetic field. When $s-$ and $d-$ condensates have a 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-T${}_c$ 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 $s+is$ and $s+id$ superconducting phases.

13 pages, 7 figures

References in corpus (15)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• Chiral P-Wave Order in Sr_2RuO_4
• Pairing State with a time-reversal symmetry breaking in FeAs based superconductors
• Nodeless pairing in superconducting copper-oxide monolayer films on Bi2Sr2CaCu2O8+δ
• Quasiparticle Heat Transport in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$: Evidence for a k-dependent Superconducting Gap without Nodes
• Chiral CP^2 skyrmions in three-band superconductors
• Emergent phenomena in multicomponent superconductivity: an introduction to the focus issue
• Vortex sub-lattice melting in a two-component superconductor
• Spontaneous currents in a superconductor with s+is symmetry
• Ground state, collective mode, phase soliton and vortex in multiband superconductors
• Distinguishing between $s+id$ and $s+is$ pairing symmetries in multiband superconductors through spontaneous magnetization pattern induced by a defect
• Giant vortex and Skyrmion in a rotating two-species Bose-Einstein condensate
• Topological phase transitions in small mesoscopic chiral p-wave superconductors
• Vortex chains due to nonpairwise interactions and field-induced phase transitions between states with different broken symmetry in superconductors with competing order parameters