Half-flux quanta and vortex-antivortex pairs in two-band superconductors
Department of Physics, Shanghai University - 99 Shangda Road, Shanghai 200444, China
Received: 4 March 2013
Accepted: 9 April 2013
Vortex states of two-band superconductors are investigated based on the microscopic Ginzburg-Landau model. We show that the nonlocal interband coupling can lead to the breaking of translation symmetry and the axial rotation symmetry of the conventional Abrikosov vortex states, resulting in a novel vortex structure comprising a mixture of triangle and square-like vortex lattices that have no counterparts in the single-band superconductors. Half-quantized vortices and stable vortex-antivortex pairs are found. These results may relate to the experimental observations of anomalous vortex structures in the two-band magnesium diboride superconductor.
PACS: 74.25.Ha – Magnetic properties including vortex structures and related phenomena / 74.20.De – Phenomenological theories (two-fluid, Ginzburg-Landau, etc.) / 74.25.Uv – Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses)
© EPLA, 2013