Induction of non-d-wave order-parameter components by currents in d-wave superconductors

TL;DR

This paper demonstrates that supercurrents in d-wave superconductors induce non-d-wave order-parameter components, altering the gap structure and node lines, with implications for understanding supercurrent effects on unconventional superconductors.

Contribution

It provides a theoretical analysis within Ginzburg-Landau theory showing supercurrents induce s-wave and d_{xy} components, modifying the order parameter's structure in d-wave superconductors.

Findings

Supercurrents induce non-d-wave order components.

Order parameter remains gapless despite modifications.

The magnitude of induced s-wave component is estimated.

Abstract

It is shown, within the framework of the Ginzburg-Landau theory for a superconductor with d_{x^2-y^2} symmetry, that the passing of a supercurrent through the sample results, in general, in the induction of order-parameter components of distinct symmetry. The induction of s-wave and d_{xy(x^2-y^2)-wave components are considered in detail. It is shown that in both cases the order parameter remains gapless; however, the structure of the lines of nodes and the lobes of the order parameter are modified in distinct ways, and the magnitudes of these modifications differ in their dependence on the (a-b plane) current direction. The magnitude of the induced s-wave component is estimated using the results of the calculations of Ren et al. [Phys. Rev. Lett. 74, 3680 (1995)], which are based on a microscopic approach.