Charged fixed point found in superconductor below T(c)
Oct, 2001Citations per year
Abstract: (Elsevier)
We present a semi-perturbative approach which yields an infrared-stable fixed point in the Ginzburg–Landau for N =2, where N /2 is the number of complex components. The calculations are done in d =3 dimensions and below T c , where the renormalization group functions can be expressed directly as functions of the Ginzburg parameter κ which is the ratio between the two fundamental scales of the problem, the penetration depth λ and the correlation length ξ . We find a charged fixed point for κ>1/ 2 , that is, in the type II regime, where Δ κ≡κ−1/ 2 is shown to be a natural expansion parameter. This parameter controls a momentum space instability in the two-point correlation function of the order field. This instability appears at a non-zero wave-vector p 0 whose magnitude scales like ∼ Δ κ β ̄ , with a critical exponent β ̄ =1/2 in the one-loop approximation, a behavior known from magnetic systems with a Lifshitz point in the phase diagram. This momentum space instability is argued to be the origin of the negative η -exponent of the order field.Note:
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