Spin Liquid Ground State in the Frustrated Kagome Antiferromagnet MgCu3(OH)6Cl2

TL;DR

This study investigates a new kagome antiferromagnet, MgCu3(OH)6Cl2, revealing it as a promising candidate for a quantum spin liquid with no magnetic order down to very low temperatures and exhibiting unconventional spin dynamics.

Contribution

The paper reports muSR experiments on MgCu3(OH)6Cl2, demonstrating its potential as a spin liquid candidate and providing detailed insights into its spin dynamics and defect-related behaviors.

Findings

No magnetic ordering down to 20 mK

Unconventional spin dynamics observed

Proposed defect-based interpretation for dynamics

Abstract

We report muSR experiments on Mg{x}Cu{4-x}(OH)6Cl2 with x \sim 1, a new material isostructural to Herbertsmithite exhibiting regular kagome planes of spin 1/2 (Cu^{2+}), and therefore a candidate for a spin liquid ground state. We evidence the absence of any magnetic ordering down to 20 mK (\sim J/10^4). We investigate in detail the spin dynamics on well characterized samples in zero and applied longitudinal fields and propose a low T defect based interpretation to explain the unconventional dynamics observed in the quantum spin liquid phase.