Coexisting spinons and magnons in frustrated zigzag spin-1/2 chain compound $\beta$-TeVO$_4$

TL;DR

This study reveals the coexistence of magnons and spinons in the frustrated zigzag spin-1/2 chain compound $eta$-TeVO$_4$, combining experimental neutron scattering data with theoretical modeling to understand its complex magnetic excitations.

Contribution

It provides a minimal exchange-network model explaining the dominant intrachain interactions, anisotropies, and weak interchain couplings in $eta$-TeVO$_4$.

Findings

Observation of coexisting magnon and spinon excitations.

Reproduction of experimental spectra using combined theoretical approaches.

Identification of key exchange interactions and anisotropies.

Abstract

We investigate magnetic excitations in the frustrated zigzag spin-1/2 chain compound $\beta$-TeVO$_4$ by inelastic neutron scattering. In the magnetically ordered ground state, the excitation spectrum exhibits coexisting magnon dispersion, characteristic of long-range magnetic order, and a spinon-like continuum that prevails above 2 meV, indicating the dominance of intrachain interactions. Combining linear-spin-wave-theory and pre-calculated spinon-continuum results, we reproduce the experimental spectrum. Our analysis offers a minimal exchange-network model which determines dominant intrachain interactions, their anisotropies and weak interchain interactions. The obtained parameters explain the magnetic ordering vector and spin excitations in the magnetic ground state.