Kosterlitz-Thouless transition in layered high-Tc superconductors

Current-temperature phase diagram of layered superconductors

“…Because the disorder does not affect the recursion relations of the system parameters p 2 , λ and y and the disorder parameter ∆ is irrelevant, our results show that a weak, random, one-body potential has no effect on the critical behavior of the system in agreement with the results of Ref. [42]. This is expected since even with one vortex in a pair pinned, the pair can still unbind because of the "freedom" of the other vortex.…”

“…Rubinstein et al [39] and Korshunov [40] have studied the effects of a random configuration of quenched vortex pairs. José [41] has investigated the 2D ferromagnetic planar model where the coupling is taken to be a random variable while Fischer [42] has studied a system where the disorder is introduced via the fugacity. The effect of a quenched, random one-body potential on a onecomponent vortex gas (i.e., no antivortices) has been considered by Menon and Dasgupta [43] and we will follow their notation here.…”

“…The effect of this averaging is to introduce an interaction between vortices in different replicas which includes the standard logarithmic interaction in addition to a short ranged disorder induced interaction which is proportional to −β∆δ(|r− r ′ |) as described in more detail in Ref. [43] After this averaging, the model is similar to that of Fischer [42] except the additional disorder induced interaction is long ranged there.…”