Volume 77, Number 2, January 2007
Article Number 27007
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 18 January 2007
EPL, 77 (2007) 27007
DOI: 10.1209/0295-5075/77/27007

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

K. Haule and G. Kotliar

Department of Physics, Rutgers University - Piscataway, NJ 08854, USA

received 26 October 2006; accepted in final form 23 November 2006; published January 2007
published online 18 January 2007

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.

71.27.+a - Strongly correlated electron systems; heavy fermions .
71.30.+h - Metal-insulator transitions and other electronic transitions .

© Europhysics Letters Association 2007