Anomalous Nernst and Righi-Leduc Effects in Mn3Sn:Berry Curvature and Entropy Flow
· Invited
Abstract
In addition to the ordinary Hall effect, the transverse electric field generated by a longitudinal charge current in the presence of a magnetic field. In ferromagnetic solids, there is an additional component to the transverse current generated by an electric field in presence of magnetic field. This Anomalous Hall effect (AHE) is a result of the Berry curvature of the Bloch waves. Recently, following theoretical propositions [1], a large AHE has been observes in noncollinear antiferromagnets Mn3Sn and Mn3Ge [2-4].
We will present a study of thermoelectric and thermal response in Mn3Sn beyond electric measurement. We measured Nernst and Righi-Leduc (or thermal hall) effects, and compared their anomalous components to their Hall counterpart. We found that the anomalous Nernst and Hall conductivities are strongly temperature-dependent and their ratio is 15 µV/K at room temperature and peaks to 50µV/K, close to kB/e(= 86 µV/K) . We found that the thermal and electrical Hall conductivities respect the Wiedemann-Franz law, and in contrast to conventional ferromagnets, the anomalous Lorenz number remains close to the Sommerfeld number over the whole temperature range of study [5].
1.H. Chen, Q. Niu, and A. MacDonald, Phys. Rev. Lett. 112, 017205 (2014); J. Kübler and C. Felser, Europhys. Lett. 108, 67001 (2014).
2.S. Nakatsuji, N. Kiyohara, and T. Higo, Nature 527, 212 (2015).
3.A. K. Nayak et al., Sci. Adv. 2: e1501870 (2016).
4.N. Kiyohara, T. Tomita, and S. Nakatsuji, Phys. Rev. Appl. 5, 064009 (2016).
5.X. Li, L. Xu, L. Ding, J. Wang, M. Shen, X. Lu, Z. Zhu and K . Behnia, Phys. Rev. Lett. 119, 056601 (2017)
We will present a study of thermoelectric and thermal response in Mn3Sn beyond electric measurement. We measured Nernst and Righi-Leduc (or thermal hall) effects, and compared their anomalous components to their Hall counterpart. We found that the anomalous Nernst and Hall conductivities are strongly temperature-dependent and their ratio is 15 µV/K at room temperature and peaks to 50µV/K, close to kB/e(= 86 µV/K) . We found that the thermal and electrical Hall conductivities respect the Wiedemann-Franz law, and in contrast to conventional ferromagnets, the anomalous Lorenz number remains close to the Sommerfeld number over the whole temperature range of study [5].
1.H. Chen, Q. Niu, and A. MacDonald, Phys. Rev. Lett. 112, 017205 (2014); J. Kübler and C. Felser, Europhys. Lett. 108, 67001 (2014).
2.S. Nakatsuji, N. Kiyohara, and T. Higo, Nature 527, 212 (2015).
3.A. K. Nayak et al., Sci. Adv. 2: e1501870 (2016).
4.N. Kiyohara, T. Tomita, and S. Nakatsuji, Phys. Rev. Appl. 5, 064009 (2016).
5.X. Li, L. Xu, L. Ding, J. Wang, M. Shen, X. Lu, Z. Zhu and K . Behnia, Phys. Rev. Lett. 119, 056601 (2017)
*This work was supported by the 1000 Youth Talents Plan, the National Science Foundation of China (Grant No. 11574097), the National Key Research and Development Program of China (Grant No. 2016YFA0401704), and China High-End Foreign Expert Programme, the 111 Project (B13033) and Fonds-ESPCI-Paris.
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Presenters
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Xiaokang Li
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology