Optical conductivity and kinetic energy of the superconducting state: A cluster dynamical mean field study

We study the evolution of the optical conductivity in the t-J model with temperature and doping using the Cluster Dynamical Mean Field Method. The transition to the superconducting state in the overdoped regime is characterized by an increase in the kinetic energy of the system, in contrast to the underdoped side where kinetic energy of the system decreases upon condensation. In the underdoped and optimally doped regime, the optical conductivity displays anomalous transfers of spectral weight over a broad frequency region.