e report measurements of long ranged supercurrents through ferromagnetic and fully spin-polarized CrO2 deposited on TiO2 substrates. In earlier work, we found supercurrents in films grown on sapphire but not on TiO2. Here we employed a special contact arrangement, consisting of a Ni/Cu sandwich between the film and the superconducting amorphous Mo70Ge30 electrodes. The distance between the contacts was almost a micrometer, and we find the critical current density to be significantly higher than found in the films deposited on sapphire. We argue this is due to spin mixing in the Ni/Cu/CrO2 layer structure, which is helpful in the generation of the odd-frequency spin triplet correlations needed to carry the supercurrent.
@article{arxiv.1111.5809,
title = {Long range spin supercurrents in ferromagnetic CrO$_2$ using a multilayer contact structure},
author = {M. S. Anwar and M. Veldhorst and A. Brinkman and J. Aarts},
journal= {arXiv preprint arXiv:1111.5809},
year = {2015}
}