Crossover from normal (N) Ohmic subdivision to superconducting (S) equipartition of current in parallel conductors at the N-S transition: Theory

Abstract

The recently observed (S. Sarangi et al., J. Phys. Condens. Matter, 18 (2006) L143) equipartition of current in parallel at and below the Normal-Superconducting (N-S) transition can be understood in terms of a Landau-Ginzburg order-parameter phenomenology. This complements the explanation proposed earlier (see Sarangi et al.) based on the flux-flow resistance providing a nonlinear negative current feedback towards equipartition when the transition is approached from above. The present treatment also unifies the usual textbook inductive subdivision expected much below Tc, and the equipartition as Tc is approached from below. The question of metastability is also briefly discussed.