Effects of vorticity and impurity on NMR relaxation rate in chiral p-wave superconductors

Abstract

In order to study site-selective NMR in chiral p-wave superconductors, we calculate local nuclear relaxation rate T1−1 in the vortex lattice state by Eilenberger theory with and without non-magnetic impurity scattering in the Born limit and unitary limit. The local T1−1 in the NMR resonance line shape is different between two chiral states p±, depending on whether the chirality is parallel or anti-parallel to the vorticity. In the p−-wave, anomalous suppression of local T1−1 occurs around the vortex core due to the negative coherence term coming from odd-frequency s-wave Cooper pair induced around the vortex. We especially examine the site dependence of the anomalous suppression of local T1−1, including the applied magnetic field dependence and the impurity effects.