How to detect fluctuating order in the high-temperature superconductors

TL;DR

This paper explores methods to detect fluctuating stripe order in high-temperature superconductors, analyzing experimental data and comparing weak and strong coupling perspectives to better understand the nature of stripe phenomena.

Contribution

It introduces strategies for extracting local order information from experiments and applies them to model systems and cuprate superconductors, favoring a strong coupling interpretation.

Findings

Stripe correlations are widespread in cuprates.

Strategies effectively analyze neutron scattering and STM data.

Strong coupling perspective better explains stripe phenomena.

Abstract

We discuss fluctuating order in a quantum disordered phase proximate to a quantum critical point, with particular emphasis on fluctuating stripe order. Optimal strategies for extracting information concerning such local order from experiments are derived with emphasis on neutron scattering and scanning tunneling microscopy. These ideas are tested by application to two model systems - the exactly solvable one dimensional electron gas with an impurity, and a weakly-interacting 2D electron gas. We extensively review experiments on the cuprate high-temperature superconductors which can be analyzed using these strategies. We adduce evidence that stripe correlations are widespread in the cuprates. Finally, we 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. We present quantitative indicators that the latter view better accounts for the observed stripe phenomena in the cuprates.