# $\mu$SR study of triangular Ising antiferromagnet ErMgGaO$_{4}$

## TL;DR

This study investigates the magnetic properties of ErMgGaO$_{4}$, revealing evidence of a quantum spin liquid state through various measurements including $bc$SR, susceptibility, and specific heat, with no magnetic order detected down to 25 mK.

## Contribution

The paper provides the first detailed magnetic characterization of ErMgGaO$_{4}$, demonstrating its quantum spin liquid behavior using $bc$SR and thermodynamic measurements.

## Key findings

- No magnetic order above 0.5 K
- Persistent spin fluctuations down to 25 mK
- Evidence supporting quantum spin liquid state

## Abstract

We present a detailed magnetic study of the triangular antiferromagnet ErMgGaO$_4$. A point charge calculation under the single ion approximation reveals a crystal field ground state doublet with a strong Ising-like behavior of the Er$^{3+}$ moment along the c axis. Magnetic susceptibility and specific heat measurements indicate no presence of magnetic transitions above 0.5~K and no evidence of residual entropy as temperature approaching zero. Zero field (ZF) $\mu$SR measurements shows no sign of static uniform or random field and longitudinal field (LF) $\mu$SR measurements exhibit persistent spin fluctuations down to our lowest temperature of 25~mK. Our results provide evidence of a quantum spin liquid state in the triangular antiferromagnet ErMgGaO$_4$.