铜氧化物高温超导体正常态反常光电导性质的研究

在全电荷自旋重组的模型下,计算了铜氧化物高温超导体正常态的光电导性质,发现在欠掺杂和最佳掺杂区,铜氧化物高温超导体正常态的光电导谱由低能端的non-Drude峰和较高能量处的中红外带两部分组成,低能峰和中红外带之间存在电荷转移能隙.随着掺杂量的增加,中红外带不断移向低能峰,最后在极过掺杂时完全融入低能峰,光电导谱恢复为Drude形式.全电荷自旋重组模型下的自能体现了部分关联效应,包含了赝能隙的信息,被认为造成了光电导的反常特性.

Anomalous Behavior of Optical Conductivity Across the Phase Diagram of Cuprate Superconductors

The doping dependence of the optical conductivity of cuprate superconductors in the normal-state is studied within the full charge-spin recombination model. It is shown that the conductivity spectrum in the underdoped and optimally doped regimes contains the low-energy non-Drude peak and unusual midinfrared band. However, the position of the midinfrared band shifts towards the low-energy non-Drude peak with increasing doping. In particular, the low-energy non-Drude peak incorporates with the midinfrared band in the heavily overdoped regime, and then the low-energy Drude behavior recovers. The striking behavior of the optical conductivity is believed closely related to the pseudogap which is contained in self-energy in the full charge-spin recombination model.