Role ofd-wave pairing inA15 superconductors

Abstract

We argue that the recent Raman spectroscopy observation of a sharp mode in $s$-wave superconducting V${}_{3}$Si is due to a competing $d$-wave pairing state. We present microscopic arguments for the origin of this $d$-wave order. We further argue that the $d$-wave order explains the observed shrinking of the vortex core structure at anomalously low magnetic fields and the large anisotropy observed in the upper critical field.