Universal Spin Response in Copper Oxide Materials

TL;DR

This paper investigates the universal behavior of spin responses in copper oxide materials at finite temperatures, revealing temperature-independent spin structure factors and universal susceptibility behavior consistent with experiments.

Contribution

It introduces a fermion-spin theory framework to explain the universal spin response in copper oxides, highlighting temperature-independent features and specific susceptibility behavior.

Findings

Integrated dynamical spin structure factor is nearly temperature independent.

Integrated susceptibility exhibits a universal arctan behavior.

Spin-lattice relaxation time is weakly temperature dependent.

Abstract

The spin response in the copper oxide materials at finite temperatures in the underdoped and optimal doped regimes is studied within the framework of the fermion-spin theory. The integrated dynamical spin structure factor is almost temperature independent, the integrated susceptibility shows the particularly universal behavior as $I(\omega, T) \propto arctan [ a_{1}\omega/T + a_{3}(\omega/T)^{3}]$, and the spin-lattice relaxation time is weakly temperature dependent, which are consistent with experiments and numerical simulations.