Optical Conductivity in the Copper Oxide Materials

Abstract

The frequency- and temperature-dependent optical conductivity of the copper oxide materials in the underdoped and optimal doped regimes are studied within the t-J model. The conductivity spectrum shows the unusual behavior at low energies and anomalous midinfrared peak in the low temperatures. However, this midinfrared peak is severely depressed with increasing temperatures, and vanishes at higher temperatures.Comment: 11 pages, Revtex, Two figures are not included, and can be obtained by reques