Angular Fluctuations of a Multicomponent Order Describe the Pseudogap of YBa 2 Cu 3 O 6+ x

Abstract

The Cuprate Pseudogap The properties of copper-oxide superconductors are changed by chemical doping, but, if doping is suboptimal, the transition temperature T c drops. Conversely, the so-called pseudogap, a depression in the density of states around the Fermi level that may or may not be related to superconductivity, gains strength. The cuprate YBa 2 Cu 3 O 6+x shows a charge density order that grows as T c is approached from both low and high temperatures. Hayward et al. (p. 1336 ) have developed a model in which classical fluctuations of a six-component order parameter, encompassing both superconducting and charge orders, reproduce the characteristic concave temperature dependence of the x-ray scattering intensity and thus provide a framework for the understanding of the pseudogap regime.