Interplay of thermal and quantum spin fluctuations on the kagome lattice

TL;DR

This study uses Raman spectroscopy to explore the magnetic excitations in Herbertsmithite, revealing evidence supporting a spin liquid ground state influenced by thermal and quantum spin fluctuations on the kagome lattice.

Contribution

It provides experimental Raman data on Herbertsmithite's magnetic excitations, highlighting the interplay of thermal and quantum fluctuations in a perfect kagome lattice.

Findings

Identification of two dominant magnetic excitation components

Observation of a linear low-energy slope in the spectrum

Data consistent with a spin liquid ground state

Abstract

We present a Raman spectroscopic investigation of the Herbertsmithite ZnCu3(OH)6Cl2, the first realization of a Heisenberg s=1/2 antiferromagnet on a perfect kagome lattice. The magnetic excitation spectrum of this compound is dominated by two components, a high temperature quasi elastic signal and a low temperature, broad maximum. The latter has a linear low energy slope and extends to high energy. We have investigated the temperature dependence and symmetry properties of both signals. Our data agree with previous calculations and point to a spin liquid ground state.