Vortex matter in U(1)xU(1)xZ(2) phase-separated superconducting condensates
2014 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 90, no 21, 214524- p.Article in journal (Refereed) Published
We study the properties of vortex solutions and magnetic response of two-component U(1)xU(1)xZ(2) superconductors, with phase separation driven by intercomponent density-density interaction. Such a theory can be viewed arising from the breakdown of SU(2) symmetry by a biquadratic interaction between the components of the field. Depending on the symmetry-breaking term, there are two ground-state phases: one where both components of the doublet are equal (the miscible phase) and one where only one component assumes a nonzero vacuum expectation value (the immiscible state). In the latter phase, the spectrum of topological excitations contains both domain walls and vortices. We show the existence of another kind of excitation that has properties of both topological excitations at the same time. This kind of excitation combines vorticity together with a circular domain wall, interpolating between inequivalent broken states, that shows up as a ring of localized magnetic flux. Asymptotically, this resembles a vortex carrying multiple flux quanta, but because the magnetic field is localized at a given distance from the center this looks like a pipe. The isolated multiquanta pipelike vortices can be either stable or metastable, even if the system is not type 1. We discuss the response of such a system to an externally applied magnetic field. Also we discuss magnetic response of SU(2) superconductor.
Place, publisher, year, edition, pages
2014. Vol. 90, no 21, 214524- p.
Semilocal Strings, Stability
IdentifiersURN: urn:nbn:se:kth:diva-159373DOI: 10.1103/PhysRevB.90.214524ISI: 000347121800006OAI: oai:DiVA.org:kth-159373DiVA: diva2:785441
FunderKnut and Alice Wallenberg FoundationSwedish Research Council, 642-2013-7837 325-2009-7664
QC 201502032015-02-032015-01-292015-02-03Bibliographically approved