Spin dynamics in quasi-one-dimensional antiferromagnets

Theoretically challenging, the understanding of the dynamical response in quantum antiferromagnets is of great interest, in particular for both inelastic neutron scattering (INS) and nuclear magnetic resonance (NMR) experiments. In such a context, we theoretically address this question for quasi-one-dimensional quantum magnets, e.g., weakly coupled spin chains for which many compounds are available in nature. In this class of systems, the dimensional crossover between a three-dimensional ordered regime at low temperature towards one-dimensional physics at higher temperature is a nontrivial issue, notably difficult concerning dynamical properties. We present a comprehensive theoretical study based on both analytical calculations and numerical simulations which allows us to describe the full temperature crossover for the NMR relaxation rate 1/T1 or the dynamical structure factor probed by INS, from one-dimensional Tomonaga-Luttinger liquid physics to the three-dimensional ordered regime, as a function of interchain couplings [1].

[1] M. Dupont, S. Capponi, N. Laflorencie, E. Orignac, Phys. Rev. B 98, 094403 (2018)