Quantum Statistics of Interacting Dimer Spin Systems

TL;DR

This paper investigates the temperature-dependent triplet dispersion in the dimerized quantum spin system TlCuCl3 using neutron scattering, validating a specific quantum statistical model for finite-temperature many-body correlations.

Contribution

It demonstrates that the model by Troyer, Tsunetsugu, and Wuertz accurately describes finite-temperature quantum statistics in dimer spin systems.

Findings

The triplet dispersion varies with temperature as measured by neutron scattering.

Theoretical comparison confirms the validity of the Troyer et al. model at finite temperatures.

Many-body correlations are crucial for understanding the system's behavior.

Abstract

The compound TlCuCl3 represents a model system of dimerized quantum spins with strong interdimer interactions. We investigate the triplet dispersion as a function of temperature by inelastic neutron scattering experiments on single crystals. By comparison with a number of theoretical approaches we demonstrate that the description of Troyer, Tsunetsugu, and Wuertz [Phys. Rev. B 50, 13515 (1994)] provides an appropriate quantum statistical model for dimer spin systems at finite temperatures, where many-body correlations become particularly important.