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DOE OSTI · 1976178

Dielectric Relaxation by Quantum Critical Magnons

Flavián, Daniel·Volkov, Pavel A.·Hayashida, S.·Povarov, K. Yu.·Gvasaliya, S.·Chandra, Premala·Zheludev, A.
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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. Furthermore, our study demonstrates the electrical activity of coupled low-energy spin and lattice excitations, an example of quantum multiferroic behavior.

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1-dimensional spin chains75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYAntiferromagnetismCapacitanceCritical phenomenaCrystallographyDielectric propertiesDielectric relaxationDielectric spectroscopyDilution refrigeratorFerroelectricityFrustrated magnetismMagnetic couplingMagnetic phase transitionsMagnetismMagnetoelectric effectMagnonsPermittivityPhase transitionsQuantum criticalityQuantum phase transitions

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Flavián, Daniel, Volkov, Pavel A., Hayashida, S., Povarov, K. Yu., Gvasaliya, S., Chandra, Premala, Zheludev, A.. 2023-05-26. Dielectric Relaxation by Quantum Critical Magnons. https://doi.org/10.1103/physrevlett.130.216501

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