Exchange mechanism for electron paramagnetic resonance of individual adatoms

TL;DR

This paper introduces a universal mechanism enabling the control of individual atomic spins using a spin-polarized STM with electrical oscillations, advancing quantum sensing techniques.

Contribution

It proposes a new exchange-based mechanism for electrically driven ESR of single atoms, supported by theoretical calculations, expanding the potential of ESR-STM applications.

Findings

The mechanism explains recent ESR observations of Fe atoms on MgO/Ag(100).

It demonstrates control of atomic spins via electrically driven exchange interactions.

Lays groundwork for broader application of ESR-STM quantum sensing.

Abstract

We propose a new universal mechanism that makes it possible to drive an individual atomic spin using a spin polarized scanning tunnel microscope (STM) with an oscillating electric signal. We show that the combination of the distance dependent exchange with the magnetic tip and the electrically driven mechanical oscillation of the surface spins permits to control their quantum state. Based on a combination of density functional theory and multiplet calculations, we show that the proposed mechanism is essential to account for the recently observed electrically driven paramagnetic spin resonance (ESR) of an individual Fe atom on a MgO/Ag(100) surface. Our findings set the foundation to deploy the ESR-STM quantum sensing technique to a much broader class of systems.