Magnetic terahertz resonances above the N\'eel temperature in the frustrated kagome antiferromagnet averievite

TL;DR

This study uses time-domain magneto-THz spectroscopy to investigate magnetic resonances in the frustrated kagome antiferromagnet averievite, revealing how magnetic interactions and frustration influence THz spectral features above the Nél temperature.

Contribution

It provides the first detailed analysis of THz resonances in averievite and shows how Zn substitution suppresses these resonances, highlighting the role of magnetic frustration.

Findings

Pronounced THz resonances appear below short-range magnetic correlation onset.

Zn substitution suppresses THz resonances, indicating frustration effects.

Comparison with ESR spectroscopy clarifies magnetic and structural contributions.

Abstract

Time-domain magneto-THz spectroscopy is utilized to study the frustrated magnet averievite Cu$_{5-x}$Zn$_x$V$_2$O$_{10}$(CsCl). Pronounced THz resonances are observed in unsubstituted samples ($x=0$) when cooling below the onset of short-range magnetic correlations. The influence of external magnetic effects confirms the magnetic origin of these resonances. Increasing Zn substitution suppresses the resonances, as frustration effects dominate, reflecting the non-magnetic phases for $x> 0.25$ compounds. The temperature evolution of the THz spectra is complemented with electron spin resonance spectroscopy. This comparison allows a direct probe of the different contributions from magnetic order, frustration, and structural properties in the phase diagram of averievite. Our results illustrate the effect of magnetic interactions in THz spectra of frustrated magnets.