Type-1.5 superconductivity in muliband and other multicomponent systems


Abstract in English

Usual superconductors are classified into two categories as follows: type-1 when the ratio of the magnetic field penetration length (lambda) to coherence length (xi) with Ginzburg-Landau parameter kappa=lambda/xi <1/sqrt{2} and type-2 when kappa >1/sqrt{2}. The boundary case kappa =1/sqrt{2} is also considered to be a special situation, frequently termed as Bogomolnyi limit. Here we discuss multicomponent systems which can possess three or more fundamental length scales and allow a separate superconducting state, which was recently termed type-1.5. In that state a system has the following hierarchy of coherence and penetration lengths xi_1<sqrt{2}lambda<xi_2. We also briefly overview the works on single-component regime $kappa approx 1/sqrt{2}$ and comment on recent discussion by Brandt and Das in the proceedings of the previous conference in this series.

Download