Observation of the axion quasiparticle in 2D MnBi2Te4

Jian-Xiang Qiu, Barun Ghosh, Jan Schütte-Engel, Tiema Qian, Michael Smith, Yueh-Ting Yao, Junyeong Ahn, Yu-Fei Liu, Anyuan Gao, Christian Tzschaschel, Houchen Li, Ioannis Petrides, Damien Bérubé, Thao Dinh, Tianye Huang, Olivia Liebman, Emily M. Been, Joanna M. Blawat, Kenji Watanabe, Takashi Taniguchi, Kin Chung Fong, Hsin Lin, Peter P. Orth, Prineha Narang, Claudia Felser, Tay-Rong Chang, Ross McDonald, Robert J. McQueeney, Arun Bansil, Ivar Martin, Ni Ni, Qiong Ma, David J. E. Marsh, Ashvin Vishwanath and Su-Yang Xu ()
Additional contact information
Jian-Xiang Qiu: Harvard University
Barun Ghosh: Northeastern University
Jan Schütte-Engel: University of California, Berkeley
Tiema Qian: University of California, Los Angeles
Michael Smith: Argonne National Laboratory
Yueh-Ting Yao: National Cheng Kung University
Junyeong Ahn: Harvard University
Yu-Fei Liu: Harvard University
Anyuan Gao: Harvard University
Christian Tzschaschel: Harvard University
Houchen Li: Harvard University
Ioannis Petrides: University of California, Los Angeles
Damien Bérubé: Harvard University
Thao Dinh: Harvard University
Tianye Huang: Harvard University
Olivia Liebman: University of California, Los Angeles
Emily M. Been: University of California, Los Angeles
Joanna M. Blawat: Los Alamos National Laboratory
Kenji Watanabe: National Institute for Materials Science
Takashi Taniguchi: National Institute for Materials Science
Kin Chung Fong: Northeastern University
Hsin Lin: Academia Sinica
Peter P. Orth: Iowa State University
Prineha Narang: University of California, Los Angeles
Claudia Felser: Max Planck Institute for Chemical Physics of Solids
Tay-Rong Chang: National Cheng Kung University
Ross McDonald: Los Alamos National Laboratory
Robert J. McQueeney: Iowa State University
Arun Bansil: Northeastern University
Ivar Martin: Argonne National Laboratory
Ni Ni: University of California, Los Angeles
Qiong Ma: Boston College
David J. E. Marsh: King’s College London
Ashvin Vishwanath: Harvard University
Su-Yang Xu: Harvard University

Nature, 2025, vol. 641, issue 8061, 62-69

Abstract: Abstract The axion is a hypothetical fundamental particle that is conjectured to correspond to the coherent oscillation of the θ field in quantum chromodynamics1,2. Its existence would solve multiple fundamental questions, including the strong CP problem of quantum chromodynamics and dark matter, but the axion has never been detected. Electrodynamics of condensed-matter systems can also give rise to a similar θ, so far studied as a static, quantized value to characterize the topology of materials3–5. Coherent oscillation of θ in condensed matter has been proposed to lead to physics directly analogous to the high-energy axion particle—the dynamical axion quasiparticle (DAQ)6–23. Here we report the observation of the DAQ in MnBi2Te4. By combining a two-dimensional electronic device with ultrafast pump–probe optics, we observe a coherent oscillation of θ at about 44 gigahertz, which is uniquely induced by its out-of-phase antiferromagnetic magnon. This represents direct evidence for the presence of the DAQ, which in two-dimensional MnBi2Te4 is found to arise from the magnon-induced coherent modulation of the Berry curvature. The DAQ also has implications in light–matter interaction and coherent antiferromagnetic spintronics24, as it might lead to axion polaritons and electric control of ultrafast spin polarization6,15–20. Finally, the DAQ could be used to detect axion particles21–23. We estimate the detection frequency range and sensitivity in the millielectronvolt regime, which has so far been poorly explored.

Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41586-025-08862-x Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:641:y:2025:i:8061:d:10.1038_s41586-025-08862-x

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/s41586-025-08862-x

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().