Observation of time-reversal symmetry breaking in the band structure of altermagnetic RuO 2

• DOI: 10.1126/sciadv.adj4883
• Publication Date: 2024-01-31T18:58:21Z
• Authors: Olena Fedchenko; Jan Minár; Akashdeep Akashdeep; Sunil Wilfred D’S...; Dmitry Vasilyev; Olena Tkach; Lukas Odenbreit; Quynh Nguyen; Dmytro Kutnyakhov; Nils Wind; Lukas Wenthaus; Markus Scholz; Kai Rossnagel; Moritz Hoesch; Martin Aeschlimann; Benjamin Stadtmüller; Mathias Kläui; Gerd Schönhense; Tomas Jungwirth; Anna Birk Hellenes; Gerhard Jakob; Libor Šmejkal; Jairo Sinova; Hans-Joachim Elmers
• Keywords: T-symmetry

Altermagnets are an emerging elementary class of collinear magnets. Unlike ferromagnets, their distinct crystal symmetries inhibit magnetization while, unlike antiferromagnets, they promote strong spin polarization in the band structure. The corresponding unconventional mechanism time-reversal symmetry breaking without electronic spectra has been regarded as a primary signature altermagnetism but not experimentally visualized to date. We directly observe structure altermagnetic RuO 2 by detecting magnetic circular dichroism angle-resolved photoemission spectra. Our experimental results, supported ab initio calculations, establish microscopic basis for family interesting phenomena and functionalities fields ranging from topological matter spintronics, which based on altermagnets.