Understanding Paramagnetic Spin Correlations in the Spin-Liquid Pyrochlore Tb2Ti2O7

TL;DR

This paper investigates the complex magnetic correlations in the frustrated pyrochlore Tb2Ti2O7, revealing limitations of classical models and demonstrating a semi-quantitative theoretical approach that aligns with neutron scattering experiments.

Contribution

It introduces a model incorporating fluctuations between ground and excited states to better explain neutron scattering data in Tb2Ti2O7.

Findings

Successful semi-quantitative description of neutron scattering patterns

Identification of limitations in classical Ising models for this system

Enhanced understanding of spin correlations in frustrated magnets

Abstract

Recent elastic and inelastic neutron scattering studies of the highly frustrated pyrochlore antiferromagnet Tb2Ti2O7 have shown some very intriguing features that cannot be modeled by the local <111> classical Ising model, naively expected to describe this system at low temperatures. Using the random phase approximation to take into account fluctuations between the ground state doublet and the first excited doublet, we successfully describe the elastic neutron scattering pattern and dispersion relations in Tb2Ti2O7, semi-quantitatively consistent with experimental observations.