Pseudogap Behavior in Underdoped Cuprates

TL;DR

This paper reviews experimental and theoretical evidence suggesting pseudogap matter is a distinct phase coexisting with other states in underdoped cuprates, proposing a two-fluid model to explain magnetic susceptibility and superconducting quasiparticle fraction.

Contribution

It introduces a phenomenological two-fluid model for pseudogap behavior, providing insights into magnetic susceptibility scaling and quasiparticle participation in superconductivity.

Findings

Pseudogap matter coexists with coherent and superconducting states.

A simple scaling law for magnetic susceptibility is explained.

Estimate of quasiparticles becoming superconducting in underdoped cuprates.

Abstract

I review some of the experimental evidence and theoretical arguments that suggest that pseudogap matter is a new form of matter that coexists with coherent electron matter in the normal state and with superconducting matter below the superconducting transition temperature. I describe work in progress on a phenomenological two-fluid description of the evolution of pseudogap behavior that offers an explanation for the unexpectedly simple scaling behavior for the uniform magnetic susceptibility found in the underdoped cuprates and use this to propose a physical picture of the underdoped cuprates and to estimate the fraction of quasiparticles that become superconducting in underdoped superconductors.