Pylypovskyi Oleksandr V, Weber Sophie F, Makushko Pavlo, Veremchuk Igor, Spaldin Nicola A, Makarov Denys
Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany.
Kyiv Academic University, Kyiv 03142, Ukraine.
Phys Rev Lett. 2024 May 31;132(22):226702. doi: 10.1103/PhysRevLett.132.226702.
Antiferromagnets are normally thought of as materials with compensated magnetic sublattices. This adds to their technological advantages but complicates readout of the antiferromagnetic state. We demonstrate theoretically the existence of a Dzyaloshinskii-Moriya interaction (DMI), which is determined by the magnetic symmetry classes of Cr_{2}O_{3} surfaces with an in-plane magnetic easy axis. The DMI explains a previously predicted out-of-plane magnetization at the nominally compensated surfaces of chromia, leading to a surface-localized canted ferrimagnetism. This is in agreement with magnetotransport measurements and with density functional theory predictions that further allow us to quantify the strength of DMI. The temperature dependence of the transversal resistance for these planes shows distinct behavior in comparison with that of the Cr_{2}O_{3} c plane, which we attribute to the influence of DMI. Our Letter provides a framework to analyze surface-driven phenomena in antiferromagnets, and motivates the use of nominally compensated chromia surfaces for antiferromagnetic spintronics and magnonics.
反铁磁体通常被认为是具有补偿磁亚晶格的材料。这增加了它们的技术优势，但使反铁磁态的读出变得复杂。我们从理论上证明了Dzyaloshinskii-Moriya相互作用（DMI）的存在，它由具有面内易磁轴的Cr₂O₃表面的磁对称类决定。DMI解释了先前预测的氧化铬名义补偿表面处的面外磁化，导致表面局域倾斜铁磁性。这与磁输运测量以及密度泛函理论预测一致，后者进一步使我们能够量化DMI的强度。与Cr₂O₃ c平面相比，这些平面的横向电阻的温度依赖性表现出明显不同的行为，我们将其归因于DMI的影响。我们的论文提供了一个分析反铁磁体中表面驱动现象的框架，并推动了将名义补偿的氧化铬表面用于反铁磁自旋电子学和磁子学。
