Non-locally sensing the magnetic states of nanoscale antiferromagnets with an atomic spin sensor

TL;DR

This paper demonstrates an atomic spin sensor capable of detecting nanoscale antiferromagnets with high energy resolution and nanometer spatial precision, enabling advanced magnetic sensing applications.

Contribution

The authors develop a three-atom Fe spin sensor that detects antiferromagnets via surface-mediated interactions, surpassing thermal limits of conventional methods.

Findings

Detects nanoscale antiferromagnets up to 3 nm away

Achieves 10 micro-electronvolt energy resolution

Enables simultaneous sensing of multiple antiferromagnets

Abstract

The ability to sense the magnetic state of individual magnetic nano-objects is a key capability for powerful applications ranging from readout of ultra-dense magnetic memory to the measurement of spins in complex structures with nanometer precision. Magnetic nano-objects require extremely sensitive sensors and detection methods. Here 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 three nanometers distance and achieves an energy resolution of 10 micro-electronvolts 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.