Collective modes and electromagnetic response of a chiral superconductor

Motivated by the recent controversy surrounding the Kerr effect measurements in strontium ruthenate [J. Xia , Phys. Rev. Lett. 97, 167002 (2006)], we examine the electromagnetic response of a clean chiral p-wave superconductor. When the contributions of the collective modes are accounted for, the Hall response in a clean chiral superconductor is smaller by several orders of magnitude than previous theoretical predictions and is too small to …