Phys.org August 31, 2020
Quantum fluctuations associated with exotic orders may account for the unusual characteristics of the normal state, and possibly affect the superconductivity in Copper oxide high-TC superconductors. Using resonant inelastic X-ray scattering an international team of researchers (SLAC National Accelerator Laboratory, Stanford University, UK) had shown spectroscopic evidence of fluctuations associated with a charge order in nearly optimally doped Bi2Sr2CaCu2O8+δ. In the superconducting state the interplay between charge order fluctuations and bond-stretching phonons increases, an observation that is incompatible with expectations for competing orders. They argue that this behaviour reflects the properties of a dissipative system near an order–disorder quantum critical point, where the dissipation varies with the opening of the pseudogap and superconducting gap at low temperatures, leading to the proliferation of quantum critical fluctuations, which melt charge order…read more. TECHNICAL ARTICLE
Much like black holes (bottom right) are singularities in space, quantum critical points (QCPs) are point-like intersections between different states of a quantum material where all sorts of strange electron behavior are predicted to occur… Credit: Greg Stewart/SLAC National Accelerator Laboratory