2018年11月
Giant anomalous Nernst effect and quantum-critical scaling in a ferromagnetic semimetal
Nature Physics
- 巻
- 14
- 号
- 11
- 開始ページ
- 1119
- 終了ページ
- 1124
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1038/s41567-018-0225-6
- 出版者・発行元
- Springer Science and Business Media LLC
In conducting ferromagnets, an anomalous Nernst effect-the generation of an electric voltage perpendicular to both the magnetization and an applied temperature gradient-can be driven by the nontrivial geometric structure, or Berry curvature, of the wavefunction of the electrons(1,2). Here, we report the observation of a giant anomalous Nernst effect at room temperature in the full-Heusler ferromagnet Co2MnGa, an order of magnitude larger than the previous maximum value reported for a magnetic conductor(3,4). Our numerical and analytical calculations indicate that the proximity to a quantum Lifshitz transition between type-I and type-II magnetic Weyl fermions(5-7) is responsible for the observed - Tlog(T) behaviour, with T denoting the temperature, and the enhanced value of the transverse thermoelectric conductivity. The temperature dependence of the thermoelectric response in experiments and numerical calculations can be understood in terms of a quantum critical-scaling function predicted by the low-energy effective theory over more than a decade of temperatures. Moreover, the observation of an unsaturated positive longitudinal magnetoconductance, or chiral anomaly(8-10), also provides evidence for the existence of Weyl fermions(11,12) in Co2MnGa.
- リンク情報
-
- DOI
- https://doi.org/10.1038/s41567-018-0225-6
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000448973100018&DestApp=WOS_CPL
- URL
- http://www.nature.com/articles/s41567-018-0225-6
- URL
- http://www.nature.com/articles/s41567-018-0225-6.pdf
- ID情報
-
- DOI : 10.1038/s41567-018-0225-6
- ISSN : 1745-2473
- eISSN : 1745-2481
- Web of Science ID : WOS:000448973100018