Title: Evidence for triplet superconductivity near an antiferromagnetic instability in CrAs,
Abstract: 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.