Phonon thermal Hall effect in a metallic spin ice.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35933516.
- Also identified by DOI 10.1038/s41467-022-32375-0 and PMC identifier 9357082.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
It has become common knowledge that phonons can generate thermal Hall effect in a wide variety of materials, although the underlying mechanism is still controversial. We study longitudinal κ<sub>xx</sub> and transverse κ<sub>xy</sub> thermal conductivity in Pr<sub>2</sub>Ir<sub>2</sub>O<sub>7</sub>, which is a metallic analog of spin ice. Despite the presence of mobile charge carriers, we find that both κ<sub>xx</sub> and κ<sub>xy</sub> are dominated by phonons. A T/H scaling of κ<sub>xx</sub> unambiguously reveals that longitudinal heat current is substantially impeded by resonant scattering of phonons on paramagnetic spins. Upon cooling, the resonant scattering is strongly affected by a development of spin ice correlation and κ<sub>xx</sub> deviates from the scaling in an anisotropic way with respect to field directions. Strikingly, a set of the κ<sub>xx</sub> and κ<sub>xy</sub> data clearly shows that κ<sub>xy</sub> correlates with κ<sub>xx</sub> in its response to magnetic field including a success of the T/H scaling and its failure at low temperature. This remarkable correlation provides solid evidence that an indispensable role is played by spin-phonon scattering not only for hindering the longitudinal heat conduction, but also for generating the transverse response.