Bipolarity of large anomalous Nernst effect in Weyl magnet-based alloy films

Shun Noguchi; Kohei Fujiwara; Yuki Yanagi; Michi-To Suzuki; Takamasa Hirai; Takeshi Seki; Ken-ichi Uchida; Atsushi Tsukazaki

doi:10.1038/s41567-023-02293-z

Article Bipolarity of large anomalous Nernst effect in Weyl magnet-based alloy films

Shun Noguchi ; Kohei Fujiwara ; Yuki Yanagi ; Michi-To Suzuki ; Takamasa Hirai (National Institute for Materials Science) ; Takeshi Seki ; Ken-ichi Uchida (National Institute for Materials Science) ; Atsushi Tsukazaki

Download file (367 KB)
Download as zip (335 KB)

Collection

Citation

Shun Noguchi, Kohei Fujiwara, Yuki Yanagi, Michi-To Suzuki, Takamasa Hirai, Takeshi Seki, Ken-ichi Uchida, Atsushi Tsukazaki. Bipolarity of large anomalous Nernst effect in Weyl magnet-based alloy films. Nature Physics. 2024, 20 (2), 254-260. https://doi.org/10.1038/s41567-023-02293-z

(BibTeX)

Description:

(abstract)

A thermopile device converts thermal energy to electrical energy. Controlling the polarity of the thermoelectric voltage that such a device generates is an important part of enhancing its thermoelectric output. Constructing thermopile devices where the mechanism is based on the anomalous Nernst effect in topological magnets and where one can control the bipolarity is still hard to do. Here we demonstrate the bipolarity of a large anomalous Nernst effect in a series of Weyl ferromagnet Co3Sn2S2-based alloy films by tuning the Fermi energy. We illustrate the bipolarity of the anomalous Nernst signal originating from the intrinsic Berry curvature contribution by systematically regulating the Fermi energy by nickel or indium substitution while maintaining a topological band feature of the Weyl ferromagnet. The bipolarity enables the construction of the Weyl magnet-based anomalous Nernst thermopile that generates large thermoelectric output at zero magnetic field. These demonstrations of bipolar large anomalous Nernst effect in Co3Sn2S2-based films will stimulate the device development of efficient thermoelectric energy conversion exploiting topological magnets.

Rights: