Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany.
Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany.
Sci Adv. 2017 May 26;3(5):e1603137. doi: 10.1126/sciadv.1603137. eCollection 2017 May.
The ability to sense the magnetic state of individual magnetic nano-objects is a key capability for powerful applications ranging from readout of ultradense magnetic memory to the measurement of spins in complex structures with nanometer precision. Magnetic nano-objects require extremely sensitive sensors and detection methods. We create an atomic spin sensor consisting of three Fe atoms and show that it can detect nanoscale antiferromagnets through minute, surface-mediated magnetic interaction. Coupling, even to an object with no net spin and having vanishing dipolar stray field, modifies the transition matrix element between two spin states of the Fe atom-based spin sensor that changes the sensor's spin relaxation time. The sensor can detect nanoscale antiferromagnets at up to a 3-nm distance and achieves an energy resolution of 10 μeV, surpassing the thermal limit of conventional scanning probe spectroscopy. This scheme permits simultaneous sensing of multiple antiferromagnets with a single-spin sensor integrated onto the surface.
能够感知单个磁性纳米物体的磁态是实现各种强大应用的关键能力，这些应用范围从超密集磁存储的读出到纳米精度测量复杂结构中的自旋。磁性纳米物体需要极其灵敏的传感器和检测方法。我们创建了一个由三个 Fe 原子组成的原子自旋传感器，并展示了它可以通过微小的表面介导磁相互作用来检测纳米级反铁磁体。即使与没有净自旋且具有消失的偶极 stray 场的物体耦合，也会修改基于 Fe 原子的自旋传感器的两个自旋态之间的跃迁矩阵元，从而改变传感器的自旋弛豫时间。该传感器可以在长达 3nm 的距离内检测纳米级反铁磁体，并实现了 10μeV 的能量分辨率，超过了传统扫描探针光谱学的热极限。该方案允许通过集成在表面上的单个自旋传感器同时感测多个反铁磁体。
