Microscopic prediction of skyrmion lattice state in clean interface superconductors
2014 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 90, no 6, 064509- p.Article in journal (Refereed) Published
When an in-plane field is applied to a clean interface superconductor, a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO)-like phase is stabilized. This phase has a U(1)xU(1) symmetry and, in principle, this symmetry allows for flux carrying topological excitations different from Abrikosov vortices (which are the simplest defects associated with S-1 --> S-1 maps). However, in practice, largely due to electromagnetic and other intercomponent interactions, such topological excitations are very rare in superconducting systems. Here, we demonstrate that a realistic microscopic theory for interface superconductors, such as SrTiO3/LaAlO3, predicts an unconventional magnetic response where the flux-carrying objects are skyrmions, characterized by homotopy invariants of S-2 --> S-2 maps. Additionally, we show that this microscopic theory predicts that stable fractional vortices form near the boundary of these superconductors. It also predicts the appearance of type-1.5 superconductivity for some range of parameters. Central to these results is the assumption that the Rashba spin-orbit coupling is much larger than the superconducting gap.
Place, publisher, year, edition, pages
2014. Vol. 90, no 6, 064509- p.
Field, Insulator, Vortices, Order
IdentifiersURN: urn:nbn:se:kth:diva-152582DOI: 10.1103/PhysRevB.90.064509ISI: 000341267500005OAI: oai:DiVA.org:kth-152582DiVA: diva2:750567
FunderKnut and Alice Wallenberg FoundationSwedish Research Council
QC 201409292014-09-292014-09-292014-09-29Bibliographically approved