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)
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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
Authors
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Xiaokang Li
Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology