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arXiv · 1911.08122

Unidirectional Seebeck effect in magnetic topological insulators

Xiao-Qin Yu·Zhen-Gang Zhu·Gang Su
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Abstract

We theoretically investigate the temperature gradient-dependent or unidirectional Seebeck effect (USE) in a magnetic/ nonmagnetic topological insulator (TI) heterostructure with in-plane magnetization in terms of the semiclassical electron dynamics and Fermi golden rule. The USE has a quantum origin arising from the magnon asymmetric scattering of surface Dirac electrons on TI. We discuss the USE in the heterostructures, Cr$_{x}$(Bi$_{1-y}$Sb$_y$)$_{2-x}$Te$_{3}$/ (Bi$_{1-y}$Sb$_{y})_2$Te$_{3}$. The USE exhibits $\cosϕ$-dependence (measured from $y$-direction) on the orientation of magnetization. It's found that the sign of USE stays unchanged when the system is transferred from $p$-doping to $n$-doping. The USE shows on inverse-linearly temperature dependent at high temperature.

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Xiao-Qin Yu, Zhen-Gang Zhu, Gang Su. 2019-11-19. Unidirectional Seebeck effect in magnetic topological insulators. https://doi.org/10.1103/physrevb.100.195418

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