Slow spin-glass and fast spin-liquid components in quasi-two-dimensional La2(Cu,Li)O4

TL;DR

This study reveals coexistence of slow spin-glass and fast spin-liquid components in La2(Cu,Li)O4, highlighting partial spin freezing due to disorder and quantum fluctuations in a quasi-two-dimensional S=1/2 Heisenberg system.

Contribution

It uncovers a novel partial spin freezing phenomenon where only some spins freeze while others remain liquid, driven by anisotropic interactions and quantum effects.

Findings

Partial spin freezing observed in La2(Cu,Li)O4

Coexistence of spin-glass and spin-liquid states

Quantum fluctuations influence spin dynamics

Abstract

In conventional spin glasses, magnetic interaction is not strongly anisotropic and the entire spin system is believed to be frozen below the spin-glass transition temperature. In La2Cu0.94Li0.06O4, for which the in-plane exchange interaction dominates the interplane one, only a fraction of spins with antiferromagnetic correlations extending to neighboring planes become spin-glass. The remaining spins with only in-plane antiferromagnetic correlations remain spin-liquid at low temperature. Such a novel partial spin freezing out of a two-dimensional spin-liquid observed in this cold neutron scattering study is likely due to a delicate balance between disorder and quantum fluctuations in the quasi-two dimensional S=1/2 Heisenberg system.