Magnetic excitations in the 1/3 plateau state in InCu$_3$(OH)$_6$Cl$_3$

TL;DR

This study investigates the magnetic excitations in InCu$_3$(OH)$_6$Cl$_3$ within its 1/3 magnetization plateau state using NMR relaxation rates, revealing a field-dependent magnetic excitation gap crucial for understanding kagome antiferromagnets.

Contribution

The paper provides the first microscopic magnetic characterization of the 1/3 plateau state in InCu$_3$(OH)$_6$Cl$_3$ through NMR, highlighting the field-dependent magnetic excitation gap.

Findings

Identification of a magnetic excitation gap in the 1/3 plateau state.

Field dependence of the spin gap reveals insights into the microscopic origin.

NMR relaxation rates elucidate magnetic dynamics in the plateau state.

Abstract

Magnetic dynamics in InCu$_3$(OH)$_6$Cl$_3$ was investigated from the NMR relaxation rate measurement. In InCu$_3$(OH)$_6$Cl$_3$, the magnetization isotherm shows a plateau at the 1/3 of full-saturation magnetization, characterizing the 1/3 plateau state. As the 1/3 plateau state appears above 7 T upto 14 T, the microscopic magnetic properties were investigated with the NMR measurement in steady fields. The temperature and field dependence of $1/T_1$ measurement reveals a gap in the magnetic excitation spectrum and its evolution with field in the 1/3 plateau state. The field dependence of spin gap provides an important information to understand the microscopic origin of 1/3 plateau state in the kagome antiferromagnets.