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arXiv · 2406.17421

Phonon Heat Transport and Anisotropic Tuning of Quantum Fluctuations in a Frustrated Honeycomb Magnet

Haoran Fan·Yue Chen·Yuchen Gu·Yuan Li·Xi Lin
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Abstract

Honeycomb cobalt oxides containing 3$\it{d}$ Co$^{2+}$ ions might realize frustrated magnetism and novel quantum phases. Among candidate materials, Na$_{3}$Co$_{2}$SbO$_{6}$ stands out for its distorted honeycomb lattice and significant in-plane anisotropy, motivating vector-field tuning inside the honeycomb plane. Here we use thermal transport down to the mK regime to study twin-free crystals of Na$_{3}$Co$_{2}$SbO$_{6}$ subject to in-plane vector fields. We find that the thermal conductivity $\kappa$ never exceeds the heat-transport capability of phonons, rendering its suppression primarily due to phonon scattering off magnetic excitations and/or domain boundaries. The system's field-driven quantum criticality manifests itself as an abundance of magnetic fluctuations hindering the heat transport, which further depends on the field direction in an intriguing manner.

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Haoran Fan, Yue Chen, Yuchen Gu, Yuan Li, Xi Lin. 2024-06-25. Phonon Heat Transport and Anisotropic Tuning of Quantum Fluctuations in a Frustrated Honeycomb Magnet. https://arxiv.org/abs/2406.17421

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