Superconductivity was recently observed in CrAs as the helimagnetic order is suppressed by applying pressure, suggesting possible unconventional superconductivity. To reveal the nature of the superconducting order parameter of CrAs, here we report the angular dependence of the upper critical field under pressure. Upon rotating the field by 360 degrees in the bc-plane, six maxima are observed in the upper critical field, where the oscillations have both six-fold and two-fold symmetric components. Our analysis suggests the presence of an unconventional odd-parity spin triplet state.
@article{arxiv.1710.06707,
title = {Evidence for triplet superconductivity near an antiferromagnetic instability in CrAs},
author = {C. Y. Guo and M. Smidman and B. Shen and W. Wu and F. K. Lin and X. L Han and Y. Chen and F. Wu and Y. F. Wang and W. B. Jiang and X. Lu and J. P. Hu and J. L. Luo and H. Q. Yuan},
journal= {arXiv preprint arXiv:1710.06707},
year = {2018}
}