Twisted atomic all-antiferromagnetic tunnel junctions

Antiferromagnetic spintronics[1, 2] shows significant potential for high-density and ultrafast information evices since they are resistant to stray fields and up to THz dynamics due to compensated magnetization. Magnetic tunnel junctions, a key spintronic memory component that are typically formed from ferromagnetic materials, have seen rapid developments recently using non-collinear antiferromagnetic materials[3, 4], such as Mn3Pt and Mn3Sn. However, a low stray field still exists because of a small net magnetization in these non-collinear antiferromagnets.

Very recently[5], we demonstrated for the first time a novel twisting strategy for constructing allantiferromagnetic tunnel junctions down to the atomic limit. By twisting two bilayers of CrSBr, a twodimensional antiferromagnet, a more than 700% nonvolatile tunneling magnetoresistance (TMR) ratio is displayed at zero field at 2 K with the entire twisted stack acting as the tunnel barrier. This is determined by twisting two CrSBr monolayers for which the TMR is shown to be derived from accumulative coherent tunneling across the individual CrSBr monolayers. The dependence of the TMR on the twist angle is calculated from the electron parallel momentum dependent decay across the twisted monolayers. This is excellent agreement with our experiments that consider twist angles that vary from 0° to 90°. Moreover, we also find that the temperature dependence of the TMR is surprisingly much weaker for the twisted as compared to the untwisted junctions, making the twisted junctions even more attractive for applications.

Our work shows that it is possible to push nonvolatile magnetic information storage to the atomically thin limit.

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L. Liu, T. Zhang, Z. Zeng, J. Zh.ang, C. Jiang, Z. Liu, Nature. 2023, 613, 485.

[4] X. Chen, T. Higo, K. Tanaka, T. Nomoto, H. Tsai, H. Idzuchi, M. Shiga, S. Sakamoto,

R. Ando, H. Kosaki, T. Matsuo, D. Nishio-Hamane, R. Arita, S. Miwa, S. Nakatsuji, Nature. 2023, 613, 490.

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S. S. P. Parkin, Nature. 2024, 632, 1045