Deconfinement of vortices with continuously variable fractions of the unit flux quanta in two-gap superconductorsJ. Goryo, S. Soma and H. Matsukawa
Department of Physics and Mathematics, Aoyama Gakuin University - 5-10-1, Fuchinobe, Sagamihara, 229-8558, Japan
received 21 June 2007; accepted in final form 9 August 2007; published October 2007
published online 5 September 2007
We propose a new stage of confinement-deconfinement transition, which can be observed in laboratory. In two-gap superconductors (SCs), two kinds of vortex exist and each of them carries a continuously variable fraction of the unit flux quanta = hc/2e. The confined state of these two is a usual vortex and stable in the low-temperature region of the system under a certain magnetic field above Hc1. We see an analogy to quarks in a charged pion. An entropy gain causes two fractional vortices to be deconfined above a certain temperature.
74.20.De - Phenomenological theories (two-fluid, Ginzburg-Landau, etc.).
© Europhysics Letters Association 2007