Dr. Yoshiki SATO
Graduate School of Science and Engineering,
Saitama University,Saitama 338-8570, Japan.
Date & Time: 14:00 - 15:00, December 11th (Wed), 2024.
Place: 2nd conference room, Main Bldg., Sengen-site.
(The 273th Special CMSM seminar)
Large transverse thermoelectric conversion based on the mixed-dimensionality of Fermi surfaces
Dr. Yoshiki SATO
Graduate School of Science and Engineering,
Saitama University,Saitama 338-8570, Japan.
Abstract:
The transverse thermoelectric (TTE) effect, the conversion between longitudinal heat current and transverse electric current, has attracted much attention as it offers remarkable potential beyond conventional thermoelectric devices [1-3]. Currently, the most promising TTE materials are magnetic compounds with topologically non-trivial band structures. Here, we propose to utilize the dimensionality of Fermi surfaces as a new approach to developing high-performance TTE materials. In this study, we focus on the chiral crystal LaPt2B [4] as a candidate material for efficient transverse thermoelectric conversion induced by mixed-dimensional Fermi surfaces [5]. We find that LaPt2B exhibits positive thermopower for out-of-plane direction and negative thermopower for in-plane direction, namely an axis-dependent conduction polarity. The calculated Fermi surfaces of LaPt2B include quasi-1D hole and quasi-2D electron Fermi surfaces, and the mix-dimensional Fermi surfaces are closely related to the observed axis-dependent conduction polarity. We demonstrated the large transverse thermopower (10 μV/K at T = 300 K) induced by the axis-dependent conduction polarity in the mixed-dimensional conductor. We will also discuss the investigation of the Fermi surface topology using quantum oscillations and related TTE materials [6] based on the mixed-dimensionality of Fermi surfaces.
References
[1] H. J. Goldsmid, J. Electron. Mater. 40, 1254 (2011).
[2] A. Sakai et al., Nat. Phys. 14, 1119 (2018): A. Sakai et al., Nature 581, 53 (2020).
[3] K. Uchida and J. P. Heremans, Joule 6, 2240 (2022). [4] O. L. Sologub, K. Hiebl, and P. S. Salamakha, Solid State Commun. 127, 379 (2003).
[5] M. Hikari et al., Nat. Commun. 15, 3907 (2024).
[6] S. Ohsumi et al., PRX energy, in press: arXiv:2410.17687
References
[1] H. J. Goldsmid, J. Electron. Mater. 40, 1254 (2011).
[2] A. Sakai et al., Nat. Phys. 14, 1119 (2018): A. Sakai et al., Nature 581, 53 (2020).
[3] K. Uchida and J. P. Heremans, Joule 6, 2240 (2022). [4] O. L. Sologub, K. Hiebl, and P. S. Salamakha, Solid State Commun. 127, 379 (2003).
[5] M. Hikari et al., Nat. Commun. 15, 3907 (2024).
[6] S. Ohsumi et al., PRX energy, in press: arXiv:2410.17687
(Contact)
Ken-ichi Uchida, Spin Caloritronics Group
E-mail: UCHIDA.Kenichi[at]nims.go.jp
E-mail: UCHIDA.Kenichi[at]nims.go.jp