Formation of collective spins in frustrated clusters

TL;DR

This study investigates the magnetic behavior of acuvo, revealing a transition from strongly correlated atomic spins to weakly interacting pseudo-spins within frustrated clusters, using experimental measurements and exact modeling across temperatures.

Contribution

It provides a detailed characterization of the temperature-dependent magnetic properties of acuvo, highlighting the formation of collective pseudo-spins in frustrated clusters, a novel insight into frustrated magnetism.

Findings

High-temperature regime described by atomic S=1/2 spins

Transition to weakly interacting pseudo-spins at lower temperatures

Pseudo-spins form over frustrated kagome-like clusters

Abstract

Using magnetization, specific heat and neutron scattering measurements, as well as exact calculations on realistic models, the magnetic properties of the \lacuvo compound are characterized on a wide temperature range. At high temperature, this oxide is well described by strongly correlated atomic $S$=1/2 spins while decreasing the temperature it switches to a set of weakly interacting and randomly distributed entangled pseudo spins $\tilde S=1/2$ and $\tilde S=0$. These pseudo-spins are built over frustrated clusters, similar to the kagom\'e building block, at the vertices of a triangular superlattice, the geometrical frustration intervening then at different scales.