Saturation of the anomalous Hall effect at high magnetic fields in altermagnetic RuO2

Tschirner, Teresa; Keßler, Philipp; Gonzalez Betancourt, Ruben Dario; Kotte, Tommy; Kriegner, Dominik; Büchner, Bernd; Dufouleur, Joseph; Kamp, Martin; Jovic, Vedran; Smejkal, Libor; Sinova, Jairo; Claessen, Ralph; Jungwirth, Tomas; Moser, Simon; Reichlova, Helena; Veyrat, Louis

Abstract

Observations of the anomalous Hall effect in RuO2 and MnTe have demonstrated unconventional time-reversal symmetry breaking in the electronic structure of a recently identified new class of compensated collinear magnets, dubbed altermagnets. While in MnTe, the unconventional anomalous Hall signal accompanied by a vanishing magnetization is observable at remanence, the anomalous Hall effect in RuO2 is excluded by symmetry for the Néel vector pointing along the zero-field [001] easy-axis. Guided by a symmetry analysis and ab initio calculations, a field-induced reorientation of the Néel vector from the easy-axis toward the [110] hard-axis was used to demonstrate the anomalous Hall signal in this altermagnet. We confirm the existence of an anomalous Hall effect in our RuO2 thin-film samples, whose set of magnetic and magneto-transport characteristics is consistent with the earlier report. By performing our measurements at extreme magnetic fields up to 68 T, we reach saturation of the anomalous Hall signal at a field Hc ≃ 55 T that was inaccessible in earlier studies but is consistent with the expected Néel-vector reorientation field.

Citation

Tschirner, T., Keßler, P., Gonzalez Betancourt, R. D., Kotte, T., Kriegner, D., Büchner, B., …Veyrat, L. (2023). Saturation of the anomalous Hall effect at high magnetic fields in altermagnetic RuO2. APL Materials, 11(10), Article 101103. https://doi.org/10.1063/5.0160335

• Journal Article Type: Article
• Acceptance Date: Aug 31, 2023
• Online Publication Date: Oct 2, 2023
• Publication Date: 2023-10
• Deposit Date: Mar 8, 2024
• Publicly Available Date: Mar 19, 2024
• Journal: APL Materials
• Electronic ISSN: 2166-532X
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 10
• Article Number: 101103
• DOI: https://doi.org/10.1063/5.0160335
• Keywords: General Engineering; General Materials Science
• Public URL: https://nottingham-repository.worktribe.com/output/25685613
• Publisher URL: https://pubs.aip.org/aip/apm/article/11/10/101103/2913994/Saturation-of-the-anomalous-Hall-effect-at-high