International Conference on Materials and Mechanisms of Superconductivity - M2S 2012,
Speaker: J. A. Sauls
Department of Physics & Astronomy, Northwestern University, Evanston, IL 60208
Washington D.C., July 29 - August 3, 2012
Abstract: Superconductors with a multi-component order parameter can possess topologically stable vortices and inhomogeneous phases that are not possible in single-component superconductors. In this talk I describe the structure of vortices, vortex lattices and related domain walls that are possible ground states and metastable states of chiral spin-triplet superconductors.1 Among the novel vortex states are stable doubly quantized vortices and meta-stable composite mass/charge and spin vortices with half a flux quantum. Observation of these structures would provide fingerprints of broken time-reversal symmetry and/or space-inversion symmetry in multi-component, spin-triplet superconductors, such as thin films of , and widely discussed theoretical models of the ground states for Sr2RuO4, as well as heavy fermion superconductors. Theoretical results for the order parameter structures, fermionic spectrum, charge/mass/spin currents and magnetic field distributions of these vortex states are reported. Phase stability and the H-T phase diagram for vortex lattices (VL) of singly- and doubly quantized vortices in chiral spin-triplet superconductors are reported. Comparisons with small angle neutron scattering studies of the flux lattices in are presented. In particular, I discuss the role of Fermi surface anisotropy, and the point group symmetry of pairing basis states, on the energetics and stability of singly vs. doubly quantized lattices of vortices, and the implications one can draw from comparison with existing SANS measurements for the order parameter symmetry of Sr2RuO4.2,3
The research of JAS is supported by National Science Foundation Grants DMR-0805277 and DMR-1106315.
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