Field Dispersion and Strong Coupling of Nuclear-Electron Spin Excitation in MnCO$_3$

TL;DR

This paper investigates hybridized nuclear-electron spin excitations in MnCO₃, revealing strong coupling, dispersion effects, and nonlinear behavior of nuclear spin waves through microwave absorption measurements.

Contribution

It demonstrates the formation of nuclear spin waves via hyperfine interaction and characterizes their dispersion and nonlinear dynamics in MnCO₃.

Findings

Observation of strong frequency repulsion indicating hybridization

Detection of nuclear spin wave dispersion in MnCO₃

Nonlinear regime of nuclear spin resonance at high excitation power

Abstract

Hybridized nuclear and electron spin excitation in a MnCO$_3$ crystal, a weakly-anisotropic antiferromagnet, has been investigated. In this material, the hyperfine interaction is strong enough to form a nuclear spin wave. We measure the microwave absorption by a bulk MnCO$_3$ and observe the dispersion representing strong frequency repulsion between electron and nuclear modes due to their hybridization, the signature of nuclear spin wave. Additionally, we observe that the nuclear spin resonance enters a nonlinear regime above a certain excitation power, attributed to the excitation of finite wavenumber nuclear spin waves.