Probing strongly hybrid nuclear-electronic states in a model quantum ferromagnet

TL;DR

This study provides direct evidence of strongly hybridized nuclear-electronic spin states in a quantum ferromagnet, using GHz magnetic resonance techniques to explore their behavior across the phase diagram.

Contribution

It demonstrates a novel experimental approach to probe hybrid nuclear-electronic states in magnetic materials, validated by mean-field theoretical calculations.

Findings

Successful detection of hybridized states via magnetic resonance.

Comprehensive mapping of the phase diagram with theoretical agreement.

Method applicable to various rare-earth containing materials.

Abstract

We present direct local-probe evidence for strongly hybridized nuclear-electronic spin states of an Ising ferromagnet LiHoF$_4$ in a transverse magnetic field. The nuclear-electronic states are addressed via a magnetic resonance in the GHz frequency range using coplanar resonators and a vector network analyzer. The magnetic resonance spectrum is successfully traced over the entire field-temperature phase diagram, which is remarkably well reproduced by mean-field calculations. Our method can be directly applied to a broad class of materials containing rare-earth ions for probing the substantially mixed nature of the nuclear and electronic moments.