Phase textures induced by dc current pairbreaking in multilayer structures and two-gap superconductors

Abstract

We predict current-induced formation of equilibrium phase textures for a multicomponent superconducting order parameter. Using the two-component Ginzburg-Landau and Usadel equations, we show that, for weakly coupled co-moving superconducting condensates, dc current I first causes breakdown of the phase locked state at $I>I_{c1}$ followed by the formation of intrinsic phase textures well below the depairing current $I_d$. These phase textures can manifest themselves in multilayer structures, atomic Bose condensate mixtures in optical lattices and two-gap superconductors, particularly MgB$_2$, where they can result in oscillating and resistive switching effects.

Accepted for publication in PRL