%0 Journal Article
%A Fedchenko, Olena
%A Minár, Jan
%A Akashdeep, Akashdeep
%A D’Souza, Sunil Wilfred
%A Vasilyev, Dmitry
%A Tkach, Olena
%A Odenbreit, Lukas
%A Nguyen, Quynh
%A Kutnyakhov, Dmytro
%A Wind, Nils
%A Wenthaus, Lukas
%A Scholz, Markus
%A Rossnagel, Kai
%A Hoesch, Moritz
%A Aeschlimann, Martin
%A Stadtmüller, Benjamin
%A Kläui, Mathias
%A Schoenhense, Gerd
%A Jungwirth, Tomas
%A Hellenes, Anna Birk
%A Jakob, Gerhard
%A Šmejkal, Libor
%A Sinova, Jairo
%A Elmers, Hans-Joachim
%T Observation of time-reversal symmetry breaking in the band structure of altermagnetic RuO<sub>2</sub>
%J Science advances
%V 10
%N 5
%@ 2375-2548
%C Washington, DC [u.a.]
%I Assoc.
%M PUBDB-2024-00665
%M arXiv:2306.02170
%P eadj4883
%D 2024
%Z This work was funded by Deutsche Forschungsgemeinschaft (DFG) grant no. TRR 173 268565370 (projects A02, A03, A05, and B02), by the Bundesministerium für Bildung und Forschung (BMBF) (projects 05K22UM1 and 05K22UM4), by EU FET Open RIA grant no. 766566, and by Grant Agency of the Czech Republic grant no. 19-28375X. J.M. and S.W.D.S. would like to thank QM4ST project financed by the Ministry of Education, Youth and Sports of Czech Republic, project no. CZ.02.01.01/00/22_008/0004572. Q.N. acknowledges support by the Q-FARM Bloch Fellowship and the U.S. Department of Energy (DE-AC02-76SF00515).
%X Altermagnets are an emerging third elementary class of 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 of timereversal symmetry breaking without magnetization in the electronic spectra has been regarded as a primary signature of altermagnetism, but has not been experimentally visualized to date. We directly observe strong time-reversal symmetry breaking in the band structure of altermagnetic RuO<sub>2</sub> by detecting magnetic circular dichroism in angle-resolved photoemission spectra. Our experimental results, supported by ab initio calculations, establish the microscopic electronic-structure basis for a family of novel phenomena and functionalities in fields ranging from topological matter to spintronics, that are based on the unconventional time-reversal symmetry breaking in altermagnets.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:38295181
%U <Go to ISI:>//WOS:001185617600019
%R 10.1126/sciadv.adj4883
%U https://bib-pubdb1.desy.de/record/602589