Type-1.5 superconductivity in muliband and other multicomponent systems

الأصل · EN

Usual superconductors are classified into two categories as follows: type-1 when the ratio of the magnetic field penetration length (λ) to coherence length (ξ) with Ginzburg-Landau parameter κ=λ/ξ<1/√2 and type-2 when κ>1/√2. The boundary case κ=1/√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 ξ₁<√2λ<ξ₂. We also briefly overview the works on single-component regime κ≈ 1/√2 and comment on recent discussion by Brandt and Das in the proceedings of the previous conference in this series.