A study of all-electric electron spin resonance using Floquet quantum master equations

TL;DR

This paper develops a theoretical framework using Floquet quantum master equations to model electrically controlled single-atom spin dynamics, reproducing experimental features for Ti atoms on MgO/Ag and Ti-Ti systems.

Contribution

It introduces a novel Floquet quantum master equation approach to describe electrically driven spin dynamics at the atomic scale, bridging theory with experimental observations.

Findings

Reproduces experimental features of Ti atoms on MgO/Ag

Models two-atom Ti systems and their spin interactions

Explores parameter effects on atomic spin driving

Abstract

We present a theoretical framework to describe experiments directed to controlling single-atom spin dynamics by electrical means using a scanning tunneling microscope. We propose a simple model consisting of a quantum impurity connected to electrodes where an electrical time-dependent bias is applied. We solve the problem in the limit of weak coupling between the impurity and the electrodes by means of a quantum master equation that is derived by the non-equilibrium Green's function formalism. We show results in two cases. The first case is just a single atomic orbital subjected to a time-dependent electric field, and the second case consists of a single atomic orbital coupled to a second spin-1/2. The first case reproduces the main experimental features Ti atoms on MgO/Ag (100) while the second one directly addresses the experiments on two Ti atoms. These calculations permit us to explore the effect of different parameters on the driving of the atomic spins as well as to reproduce experimental fingerprints.