Uehara Taiki, Ohtsuki Takumi, Udagawa Masafumi, Nakatsuji Satoru, Machida Yo
Department of Physics, Gakushuin University, Tokyo, 171-8588, Japan.
Institute for Solid State Physics, The University of Tokyo, Kashiwa, 277-8581, Japan.
Nat Commun. 2022 Aug 6;13(1):4604. doi: 10.1038/s41467-022-32375-0.
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 and transverse κ thermal conductivity in PrIrO, which is a metallic analog of spin ice. Despite the presence of mobile charge carriers, we find that both κ and κ are dominated by phonons. A T/H scaling of κ 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 deviates from the scaling in an anisotropic way with respect to field directions. Strikingly, a set of the κ and κ data clearly shows that κ correlates with κ 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.
声子能在多种材料中产生热霍尔效应已成为常识，尽管其潜在机制仍存在争议。我们研究了PrIrO中的纵向κ和横向κ热导率，PrIrO是自旋冰的金属类似物。尽管存在可移动电荷载流子，但我们发现κ和κ均由声子主导。κ的T/H标度明确表明，纵向热流受到声子在顺磁自旋上的共振散射的显著阻碍。冷却时，共振散射受到自旋冰关联发展的强烈影响，并且κ相对于场方向以各向异性方式偏离标度。引人注目的是，一组κ和κ数据清楚地表明，κ在对磁场的响应中与κ相关，包括T/H标度的成功及其在低温下的失效。这种显著的相关性提供了确凿证据，表明自旋 - 声子散射不仅在阻碍纵向热传导方面发挥了不可或缺的作用，而且在产生横向响应方面也发挥了作用。
