Phonon Heat Transport and Anisotropic Tuning of Quantum Fluctuations in a Frustrated Honeycomb Magnet
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.
- Publication:
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arXiv e-prints
- Pub Date:
- June 2024
- DOI:
- 10.48550/arXiv.2406.17421
- arXiv:
- arXiv:2406.17421
- Bibcode:
- 2024arXiv240617421F
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 6 pages with 4 figures and 5 pages with 5 figures