Transverse Collective Excitations in Superconductors and Electromagnetic Absorption

Abstract

With use of the generalized random phase approximation an attempt is made to estimate the absorption of photons with energy less than the energy gap due to transverse collective excitations. The ratio of the surface resistance due to transverse collective excitations to that of normal metals in the extreme anomalous limit, calculated within the weak coupling theory, turns out to be too small to explain the observed data for superconducting lead and mercury. The interpretation of the collective excitations as bound pair states is briefly discussed.