Spin Susceptibility in Underdoped $\bf YBa_2Cu_3O_{6+x}$

TL;DR

This study investigates how the spin susceptibility evolves with temperature and doping in underdoped YBa2Cu3O6+x superconductors using neutron scattering, providing insights into their magnetic properties and theoretical implications.

Contribution

It offers a comprehensive neutron scattering analysis of spin susceptibility across different doping levels in underdoped YBCO, critically examining existing theories.

Findings

Spin susceptibility varies with doping and temperature.

Neutron scattering reveals detailed spin excitation spectra.

Results challenge some existing theoretical models.

Abstract

We report a comprehensive polarized and unpolarized neutron scattering study of the evolution of the dynamical spin susceptibility with temperature and doping in three underdoped single crystals of the \YBCO{6+x} high temperature superconductor: \YBCO{6.5} (Tc = 52 K), \YBCO{6.7} (Tc = 67 K), and \YBCO{6.85} (T_c = 87 K). Theoretical implications of these data are discussed, and a critique of recent attempts to relate the spin excitations to the thermodynamics of high temperature superconductors is given.