Effects of spin-flip scattering on the dynamics of the superconducting order parameter
Abstract
Measurements of the imaginary part of the pair field susceptibility chi carried out on dirty limit Al-Er alloy films are discussed. Aluminum films with erbium concentrations of up to one atomic percent were incorporated as the low T sub c film of an asymmetric Josephson junction. The excess current I sub ex due to pair tunneling was measured as a function of the bias voltage V and of the magnetic field H, applied in the plane of the junction, at temperatures within 20% of the critical temperature. Comparison to theory was facilitated by noting that chi (omega,k) varies as I sub ex (V,H) where the frequency omega and wave number k are related to V and H via the Josephson relations. The experiments represent the measurements of chi (omega,k) as a function of the pair breaking parameter rho up to 0.1. At temperatures above T sub c it was verified that the diffusive time dependent Ginzburg-Landau equation for order parameter fluctuations is valid in the presence of pair breaking. The diffusion rate was found to be reduced by the pair breaking to a value which is in quantitative agreement with theory. Additional results are detailed.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1980
- Bibcode:
- 1980PhDT........12A
- Keywords:
-
- Josephson Junctions;
- Scattering;
- Superconductivity;
- Aluminum Alloys;
- Critical Temperature;
- Electron Diffusion;
- Metal Films;
- Superconductors;
- Solid-State Physics