Nonlocal Effects on the Surface Resistance of High Temperature Superconductors with (100) and (110) Surfaces

TL;DR

This paper investigates how nonlocal effects influence the surface resistance of high-temperature d-wave superconductors, revealing that these effects depend on geometry, frequency, and scattering phase shift, and are observable under most conditions.

Contribution

It provides a detailed calculation of surface resistance considering nonlocal effects and identifies conditions under which these effects are significant and observable.

Findings

Nonlocal effects can be positive or negative depending on frequency.

Surface resistance depends strongly on geometric configuration.

Nonlocal corrections decrease with increased scattering phase shift, except near the unitarity limit.

Abstract

The low temperature surface resistance R_s of d-wave superconductors is calculated as function of frequency assuming normal state quasiparticle mean free paths l in excess of the penetration depth. Results depend strongly on the geometric configuration. In the clean limit, two contributions to R_s with different temperature dependencies are identified: photon absorption by quasiparticles and pair breaking. The size of nonlocal corrections, which can be positive or negative depending on frequency decreases for given l as the scattering phase shift \delta_N is increased. However, except in the unitarity limit \delta_N = 0.5 \pi, nonlocal effects should be observable.