Magnetic Resonance Imaging of Single Atoms

TL;DR

This paper demonstrates the first MRI of individual atoms on a surface using a cryogenic STM with single-atom ESR, achieving sub-angstrom resolution and revealing atomic magnetic interactions.

Contribution

It introduces a novel MRI technique for single atoms with unprecedented spatial resolution and insights into atomic magnetic interactions.

Findings

Successful imaging of individual atoms on a surface.

Distinct resonance signatures for different atomic species.

Detection of magnetic dipolar and exchange interactions.

Abstract

Magnetic resonance imaging (MRI) revolutionized diagnostic medicine and biomedical research by allowing a noninvasive access to spin ensembles. To enhance MRI resolution to the nanometer scale, new approaches including scanning probe methods have been used in recent years, which culminated in detection of individual spins. This allowed three-dimensional (3D) visualization of organic samples and of sophisticated spin-structures. Here, we demonstrate for the first time MRI of individual atoms on a surface. The setup, implemented in a cryogenic scanning tunneling microscope (STM), uses single-atom electron spin resonance (ESR) to achieve sub-{\AA}ngstr\"om resolution exceeding the spatial resolution of previous experiments by one to two orders of magnitude. We find that MRI scans of different atomic species and probe tips lead to unique signatures in the resonance images. These signatures reveal the magnetic interactions between the tip and the atom, in particular magnetic dipolar and exchange interaction.