Magnetic resonance in the ordered phases of the 2D frustrated quantum magnet Cs2CuCl4

TL;DR

This study investigates the evolution of electron spin resonance in Cs2CuCl4 as it transitions through its Neel temperature, revealing coexistence of spinon and antiferromagnetic resonances and complex field-induced phase transitions.

Contribution

It provides new insights into the magnetic resonance behavior and spin excitation spectra of Cs2CuCl4 in different magnetic phases and under varying field conditions.

Findings

Coexistence of spinon and antiferromagnetic resonances in the ordered phase.

Identification of two gapped branches in the low-frequency spectrum.

Complex spectra resulting from field-induced phase transitions.

Abstract

The temperature evolution of the electron spin resonance is studied at cooling the crystal samples of Cs2CuCl4 through the Neel point 0.62 K. A coexistence of the high-frequency spinon type resonance developed in the spin-liquid phase and of the low-frequency antiferromagnetic resonance was found in the ordered phase. The low-frequency magnetic resonance spectrum in the low field range has two gapped branches and corresponds well to the spectrum of spin excitations of a planar spiral spin structure with two axes of the anisotropy. The field induced phase transitions result in a more complicated low-frequency spectra.