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arXiv · 2406.01064

Antiferromagnetic order in a layered magnetic topological insulator MnBi$_2$Se$_4$ probed by resonant soft x-ray scattering

Xiang Chen·Alejandro Ruiz·Alexander J. Bishop·Brandon Gunn·Rourav Basak·Tiancong Zhu·Yu He·Mayia Vranas·Eugen Weschke·Roland K. Kawakami·Robert J. Birgeneau·Alex Frano
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Abstract

The quasi-two-dimensional magnetic topological insulator MnBi$_2$Se$_4$, stabilized via non-equilibrium molecular beam epitaxy, is investigated by resonant soft x-ray scattering. Kiessig fringes are observed, confirming a high sample quality and a thin film thickness of 10 septuple layers ($\sim$13 nm). An antiferromagnetic Bragg peak is observed at the structurally forbidden reflection, whose magnetic nature is validated by studying its temperature, energy, and polarization dependence. Through a detailed analysis, an A-type antiferromagetic order with in-plane moments is implied. This alternative spin structure in MnBi$_2$Se$_4$, in contrast to the Ising antiferromagnetic states in other magnetic topological insulators, might be relevant for hosting new topological states.

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Xiang Chen, Alejandro Ruiz, Alexander J. Bishop, Brandon Gunn, Rourav Basak, Tiancong Zhu, Yu He, Mayia Vranas, Eugen Weschke, Roland K. Kawakami, Robert J. Birgeneau, Alex Frano. 2024-06-03. Antiferromagnetic order in a layered magnetic topological insulator MnBi$_2$Se$_4$ probed by resonant soft x-ray scattering. https://doi.org/10.1103/physrevb.109.184418

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