Although ferromagnets have many applications, their large magnetization and the resulting energy cost for switching magnetic moments bring into question their suitability for reliable low-power spintronic devices. Non-collinear antiferromagnetic systems do not suffer from this problem, and often have extra functionalities: non-collinear spin order may break space-inversion symmetry and thus allow electric-field control of magnetism, or may produce emergent spin–orbit effects that enable efficient spin–charge interconversion. To harness these traits for next-generation spintronics, the nanoscale control and imaging capabilities that are now routine for ferromagnets must be developed for antiferromagnetic systems. Here, using a non-invasive, scanning single-spin magnetometer based on a nitrogen–vacancy defect in diamond, we demonstrate real-space visualization of non-collinear antiferromagnetic order in a magnetic thin film at room temperature. We image the spin cycloid of a multiferroic bismuth ferrite (BiFeO3) thin film and extract a period of about 70 nanometres, consistent with values determined by macroscopic diffraction. In addition, we take advantage of the magnetoelectric coupling present in BiFeO3 to manipulate the cycloid propagation direction by an electric field. Besides highlighting the potential of nitrogen–vacancy magnetometry for imaging complex antiferromagnetic orders at the nanoscale, these results demonstrate how BiFeO3 can be used in the design of reconfigurable nanoscale spin textures.

中文翻译：

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使用单自旋磁力计对非共线反铁磁有序进行实空间成像

尽管铁磁体有许多应用，但它们的大磁化强度和由此产生的用于切换磁矩的能量成本使其对可靠的低功率自旋电子器件的适用性产生了疑问。非共线反铁磁系统不会遇到这个问题，并且通常具有额外的功能：非共线自旋顺序可能会破坏空间反转对称性，从而允许磁场控制磁场，或者可能会产生自旋轨道效应，从而实现高效自旋电荷互变。为了将这些特性用于下一代自旋电子学，必须为反铁磁系统开发现在铁磁体常规的纳米级控制和成像能力。在这里，使用基于金刚石中氮空位缺陷的非侵入式扫描单自旋磁力计，我们展示了室温下磁性薄膜中非共线反铁磁有序的实空间可视化。我们对多铁性铋铁氧体 (BiFeO3) 薄膜的自旋摆线进行成像，并提取约 70 纳米的周期，与宏观衍射确定的值一致。此外，我们利用 BiFeO3 中存在的磁电耦合通过电场操纵摆线传播方向。除了强调氮空位磁力计在纳米级成像复杂反铁磁有序方面的潜力外，这些结果还证明了 BiFeO3 可如何用于可重构纳米级自旋纹理的设计。我们对多铁性铋铁氧体 (BiFeO3) 薄膜的自旋摆线进行成像，并提取约 70 纳米的周期，与宏观衍射确定的值一致。此外，我们利用 BiFeO3 中存在的磁电耦合通过电场操纵摆线传播方向。除了强调氮空位磁力计在纳米级成像复杂反铁磁有序方面的潜力外，这些结果还证明了 BiFeO3 可如何用于可重构纳米级自旋纹理的设计。我们对多铁性铋铁氧体 (BiFeO3) 薄膜的自旋摆线进行成像，并提取约 70 纳米的周期，与宏观衍射确定的值一致。此外，我们利用 BiFeO3 中存在的磁电耦合通过电场操纵摆线传播方向。除了突出氮空位磁力计在纳米级成像复杂反铁磁有序方面的潜力外，这些结果还证明了 BiFeO3 可如何用于可重构纳米级自旋纹理的设计。