Singularities in the optical response of cuprates - art. no. 180510

We argue that the detailed analysis of the optical response in cuprate supe rconductors allows one to verify the magnetic scenario of superconductivity in cuprates. As for strong coupling charge carriers to antiferromagnetic s pin fluctuations, the second derivative of optical conductivity should cont ain detectable singularities at 2 Delta + Delta (spin), 4 Delta, and 2 Delt a + 2 Delta (spin), where Delta is the amplitude of the superconducting gap , and Delta (s) is the resonance energy of spin fluctuations measured in ne utron scattering. We argue that there is a good chance that these singulari ties have already been detected in the experiments on optimally doped Y-Ba- Cu-O.