Qiu, J., Ghosh, B., Schütte-Engel, J., Qian, T., Smith, M., Yao, Y., Ahn, J., Liu, Y., Gao, A., Tzschaschel, C., Li, H., Petrides, I., Bérubé, D., Dinh, T., Huang, T., Liebman, O., Been, E. M., Blawat, J. M., Watanabe, K., Taniguchi, T., Fong, K. C., Lin, H., Orth, P. P., Narang, P., Felser, C., Chang, T., McDonald, R., McQueeney, R. J., Bansil, A., Martin, I., Ni, N., Ma, Q., Marsh, D. J. E., Vishwanath, A., Xu, S. (2025). Observation of the axion quasiparticle in 2D MnBi2Te4. Nature. https://doi.org/10.1038/s41586-025-08862-x