Atomic spin structures assembled by means of scanning tunneling microscopy (STM) provide valuable insight into the understanding of atomic-scale magnetism. Among the major challenges are the detection and subsequent read-out of ultrafast spin dynamics due to a dichotomy in travel speed of these dynamics and the probe tip. Here, we present a device composed of individual Fe atoms that allows for remote detection of spin dynamics. We have characterized the device and used it to detect the presence of spin waves originating from an excitation induced by the STM tip several nanometres away; this may be extended to much longer distances. The device contains a memory element that can be consulted seconds after detection, similar in functionality to e.g. a single photon detector. We performed statistical analysis of the responsiveness to remote spin excitations and corroborated the results using basic calculations of the free evolution of coupled quantum spins.

通过扫描隧道显微镜（STM）组装的原子自旋结构为了解原子尺度的磁性提供了宝贵的见识。主要挑战之一是由于超高速自旋动力学的检测和随后读出，这是由于这些动力学和探针尖端的移动速度存在二分法。在这里，我们介绍了一种由单个Fe原子组成的设备，该设备可以远程检测自旋动力学。我们已经对该设备进行了表征，并将其用于检测自数纳米以外的STM尖端引起的激发产生的自旋波的存在；这可能会延伸到更长的距离。该设备包含一个存储元件，可在检测后几秒钟进行查询，其功能类似于例如单个光子检测器。