Raman response in time reversal symmetry broken superconductors

While it is known that the amplitude and phase flucuations mix in time reversal symmetry(TRS) broken superconductors, it remains unclear what are their precise signatures in the Raman response. In this talk we will discuss the Raman response of multiband s-wave superconductor in A_1g and B_1g irreducible representations all the way across the TRS breaking transition and show that the spectrum is very rich involving the possibility of dark Leggett and Bardassis-Schreiffer modes, sensitivity to the phase of the ground state, and sensitivity to the attractive or repulsive nature of the interband interactions. We will also discuss how the spectral weights could be deduced from a new interaction-induced selection rule for Raman response of superconductors.