Are there plasminos in superconductors?
  Hot and/or dense, normal-conducting systems of relativistic fermions exhibit a particular collective excitation, the so-called plasmino. We compute the one-loop self-energy, the dispersion relation and the spectral density for fermions interacting via attractive boson exchange. It is shown that plasminos also exist in superconductors. 
Barbara Betz and Dirk H. Rischke