Superconductivity and Quantum Spin Disorder in Cuprates

TL;DR

This paper reveals a fundamental link between superconductivity and quantum spin fluctuations in underdoped cuprates, showing that Cooper pair hopping suppresses local magnetization and explaining experimental observations.

Contribution

It introduces a variational calculation demonstrating how Cooper pair hopping reduces local magnetization in cuprates, connecting spin fluctuations with superconductivity.

Findings

Cooper pair hopping significantly reduces local magnetization.

Local magnetization varies weakly with doping in the underdoped regime.

Magnetization drops sharply at the onset of superconductivity.

Abstract

A fundamental connection between superconductivity and quantum spin fluctuations in underdoped cuprates, is revealed. A variational calculation shows that {\em Cooper pair hopping} strongly reduces the local magnetization $m_0$. This effect pertains to recent neutron scattering and muon spin rotation measurements in which $m_0$ varies weakly with hole doping in the poorly conducting regime, but drops precipitously above the onset of superconductivity.