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arXiv · 2302.04234

Dielectric relaxation by quantum critical magnons

Daniel Flavián·Pavel A. Volkov·Shohei Hayashida·Kirill Yu. Povarov·Severian Gvasaliya·Premala Chandra·Andrey Zheludev
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Abstract

We report the experimental observation of dielectric relaxation by quantum critical magnons. Complex capacitance measurements reveal a dissipative feature with a temperature-dependent amplitude due to low-energy lattice excitations and an activation behavior of the relaxation time. The activation energy softens close to a field-tuned magnetic quantum critical point at $H=H_c$ and follows single-magnon energy for $H>H_c$, showing its magnetic origin. Our study demonstrates the electrical activity of coupled low-energy spin and lattice excitations, an example of quantum multiferroic behavior.

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Daniel Flavián, Pavel A. Volkov, Shohei Hayashida, Kirill Yu. Povarov, Severian Gvasaliya, Premala Chandra, Andrey Zheludev. 2023-02-08. Dielectric relaxation by quantum critical magnons. https://doi.org/10.1103/physrevlett.130.216501

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