An Introduction to Infrared Properties of High-Tc Superconductors

摘要: The essential element in the high Tc cuprate superconductors appears to be CuO2 planes which, of course must reside an electropositive environment (Tokura). Recognizing this, and focussing only on properties planes, as distinct from that their environment, allows a relatively simple picture phenomenology infrared obtained. In particular one finds normal state conductivity drops unusually slowly function frequency, more like 1/ω0.8 than conventional 1/ω2 it can described terms scattering rate is linear frequency. This frequency dependence fundamentally related temperature resisitivity, may also photoemission linewidth broad electronic background signal observed Raman experiments. superconducting characteristic energy scale -500 cm-1 (2Δ/kTc≃8) develops, reasonably identified pair-excitation threshold (superconducting gap) at low temperature. Aspects this feature which are similar different expectations based BCS theory discussed. particular, quite unusual.