Effective theory of high-temperature superconductors

TL;DR

This paper develops a field theory for high-temperature superconductors, explaining experimental superfluid density behavior in underdoped cuprates using a 3D Bose gas model.

Contribution

It introduces a comprehensive effective field theory for fluctuating d-wave superconductors and applies it to interpret superfluid density measurements in underdoped YBCO.

Findings

Superfluid density is approximately linear in temperature at low doping.

The behavior is well described by a strongly anisotropic 3D Bose gas model.

The temperature dependence slope is nearly doping-independent.

Abstract

General field theory of a fluctuating d-wave superconductor is constructed and proposed as an effective description of superconducting cuprates at low energies. The theory is used to resolve a puzzle posed by recent experiments on superfluid density in severely underdoped YBCO. In particular, the overall temperature dependence of the superfluid density at low dopings is argued to be described well by the strongly anisotropic weakly interacting three-dimensional Bose gas, and thus approximately linear in temperature with an almost doping-independent slope.