The study of the mechanism of exchange-bias phenomena and the achievement of its efficient control are of great importance, as it promotes the revelation of unique exchange interactions and the development of exotic applications. However, it is challenging due to the elusive interface between magnetic phases. In this study, we report an unprecedented exchange-bias phenomenon observed in ultrathin, uncompensated, antiferromagnetic MnBi2Te4. The magnitude and direction of the exchange field can be intentionally controlled by designing a magnetic-field sweep protocol without a field cooling process. The combined experimental and theoretical simulation results indicate that the spin-flip process assisted by the ubiquitous defect-induced pinning domain sites with varying inner exchange interactions might give rise to the emergence and robustness of this peculiar exchange bias. The temperature and thickness dependence of the exchange-bias phenomena are systematically investigated for further study and exploitation of its unique properties. This mechanism allows for highly tunable exchange bias in prevalent magnetic systems by engineering the properties of domain structures and also offers promising avenues for the design of spintronic devices combing its topology based on MnBi2Te4. Published by the American Physical Society 2024

中文翻译：

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缺陷辅助结构域成核驱动 MnBi2Te4 中独特的交换偏向现象


研究交换偏向现象的机制并实现其有效控制非常重要，因为它促进了独特交换交互的揭示和奇异应用的发展。然而，由于磁相之间难以捉摸的界面，这很有挑战性。在这项研究中，我们报告了在超薄、未补偿、反铁磁 MnBi2Te4 中观察到的前所未有的交换偏置现象。通过设计磁场扫描协议，可以有意控制交换场的大小和方向，而无需磁场冷却过程。结合实验和理论模拟结果表明，由无处不在的缺陷诱导的固定结构域位点辅助的自旋翻转过程具有不同的内部交换相互作用，可能会导致这种特殊交换偏差的出现和稳健性。系统地研究了交换偏置现象的温度和厚度依赖性，以进一步研究和开发其独特的性质。这种机制通过设计畴结构的特性，允许在流行的磁性系统中实现高度可调的交换偏压，并且还为基于 MnBi2Te4 的自旋电子器件的设计提供了有前途的途径。 美国物理学会 2024 年出版