Zeros of the order parameter of d_{x^2-y^2} superconducting film in the presence of uniform current

TL;DR

This paper investigates how a uniform current induces a p-wave component in a d-wave superconductor, affecting the energy gap and current correction, with spin-orbit coupling as a possible cause.

Contribution

It demonstrates the generation of a p-wave component in d-wave superconductors under uniform current and analyzes its effects on the energy spectrum and current correction.

Findings

P-wave component is generated by uniform current.

Energy gap behavior depends on current direction.

Spin-orbit coupling may induce the p-wave component.

Abstract

We show that additional p-wave component is generated in the pure d-wave superconductor in the presence of the uniform current. When the current flows in the antinodal direction the spectrum has a gap over all Fermi surface. If the current flows in the nodal direction, the gap opens only in the direction parallel to the current. The correction to the current due to the p-wave component of the order parameter is linear in vector potential. We show, that the spin-orbit coupling may be responsible for the additional component of the order parameter.