How to detect fluctuating stripes in the high-temperature superconductors

TLDR

Fluctuating stripe order near a quantum critical point is a key feature of quantum‑disordered high‑temperature superconductors, with debate between weak‑coupling Fermi‑liquid and strong‑coupling localized‑spin perspectives. The study derives optimal strategies to extract local stripe order information from neutron scattering and scanning tunneling microscopy experiments. The authors test these strategies on an exactly solvable one‑dimensional electron gas with an impurity, a weakly interacting two‑dimensional electron gas, and review applicable cuprate experiments. Evidence shows stripe correlations are widespread in cuprates, and quantitative indicators favor the strong‑coupling localized‑spin view over the weak‑coupling Fermi‑liquid picture.

Abstract

This article discusses fluctuating order in a quantum disordered phase proximate to a quantum critical point, with particular emphasis on fluctuating stripe order. Optimal strategies are derived for extracting information concerning such local order from experiments, with emphasis on neutron scattering and scanning tunneling microscopy. These ideas are tested by application to two model systems---an exactly solvable one-dimensional (1D) electron gas with an impurity, and a weakly interacting 2D electron gas. Experiments on the cuprate high-temperature superconductors which can be analyzed using these strategies are extensively reviewed. The authors adduce evidence that stripe correlations are widespread in the cuprates. They compare and contrast the advantages of two limiting perspectives on the high-temperature superconductor: weak coupling, in which correlation effects are treated as a perturbation on an underlying metallic (although renormalized) Fermi-liquid state, and strong coupling, in which the magnetism is associated with well-defined localized spins, and stripes are viewed as a form of micro phase separation. The authors present quantitative indicators that the latter view better accounts for the observed stripe phenomena in the cuprates.