Inelastic neutron scattering signal from deconfined spinons in a fractionalized antiferromagnet

TL;DR

This paper predicts a continuum in inelastic neutron scattering signals from deconfined spinons in a fractionalized antiferromagnet, distinct from the magnon peaks, highlighting the unique excitations in such quantum phases.

Contribution

It provides a theoretical calculation of the INS response in a fractionalized antiferromagnet, emphasizing the role of deconfined spinons and their distinguishable signals.

Findings

Spinons produce a continuum signal above the Neel gap.

Spinons contribute to the longitudinal response, absent in magnon signals.

The relative weights of spinon and magnon signals are quantitatively analyzed.

Abstract

We calculate the contribution of deconfined spinons to inelastic neutron scattering (INS) in the fractionalized antiferromagnet (AF*), introduced elsewhere. We find that the presence of free spin-1/2 charge-less excitations leads to a continuum INS signal above the Neel gap. This signal is found above and in addition to the usual spin-1 magnon signal, which to lowest order is the same as in the more conventional confined antiferromagnet. We calculate the relative weights of these two signals and find that the spinons contribute to the longitudinal response, where the magnon signal is absent to lowest order. Possible higher-order effects of interactions between magnons and spinons in the AF* phase are also discussed.