Ni Zhuoliang, Haglund A V, Wang H, Xu B, Bernhard C, Mandrus D G, Qian X, Mele E J, Kane C L, Wu Liang
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA.
Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN, USA.
Nat Nanotechnol. 2021 Jul;16(7):782-787. doi: 10.1038/s41565-021-00885-5. Epub 2021 Apr 19.
Antiferromagnets are interesting materials for spintronics because of their faster dynamics and robustness against perturbations from magnetic fields. Control of the antiferromagnetic order constitutes an important step towards applications, but has been limited to bulk materials so far. Here, using spatially resolved second-harmonic generation, we show direct evidence of long-range antiferromagnetic order and Ising-type Néel vector switching in monolayer MnPSe with large XY anisotropy. In additional to thermally induced switching, uniaxial strain can rotate the Néel vector, aligning it to a general in-plane direction irrespective of the crystal axes. A change of the universality class of the phase transition in the XY model under uniaxial strain causes this emergence of strain-controlled Ising order in the XY magnet MnPSe. Our discovery is a further ingredient for compact antiferromagnetic spintronic devices in the two-dimensional limit.
反铁磁体因其更快的动力学特性以及对磁场扰动的鲁棒性，成为自旋电子学中有趣的材料。反铁磁序的控制是迈向应用的重要一步，但迄今为止仅限于体材料。在这里，我们利用空间分辨二次谐波产生，展示了具有大XY各向异性的单层MnPSe中长程反铁磁序和伊辛型奈尔矢量切换的直接证据。除了热诱导切换外，单轴应变可以旋转奈尔矢量，使其与平面内的一般方向对齐，而与晶轴无关。单轴应变下XY模型中相变普适类的变化导致了XY磁体MnPSe中应变控制的伊辛序的出现。我们的发现是二维极限下紧凑型反铁磁自旋电子器件的又一要素。
