Quasi-universal finite-$T$ scaling in gapped one-dimensional quantum magnets

TL;DR

This study reveals a quasi-universal finite-temperature scaling behavior of gap energies and magnon lifetimes in gapped one-dimensional quantum magnets, consistent across different materials and theoretical models, over a broad temperature range.

Contribution

It demonstrates that when scaled by the zero-temperature gap, experimental and theoretical results in gapped 1D quantum magnets collapse onto a universal curve, revealing a broad quasi-universal behavior.

Findings

Experimental data show universal scaling when scaled by the zero-temperature gap.

Theoretical models agree with experimental results within a system-dependent factor.

Universal behavior persists up to approximately 1.5 times the zero-temperature gap.

Abstract

Temperature dependencies of gap energies and magnon lifetimes are measured in the quasi-1-dimensional S=1/2 gapped quantum magnets IPA-CuCl3 and Sul-Cu2Cl4 using inelastic neutron scattering. The results are compared to those found in literature for S=1 Haldane spin chain materials and to theoretical calculations for the O(3)- and O(N)- quantum non-linear sigma-models. It is found that when the T=0 energy gap Delta is used as the temperature scale, all experimental and theoretical curves are identical to within system-dependent but temperature-independent scaling factors of the order of unity. This quasi-universality extends over a surprising broad T range, at least up to kappa T ~ 1.5 Delta.