Shot noise as a probe of spin-correlated transport through single atoms

TL;DR

This paper develops a theoretical framework to analyze shot noise in tunneling currents through localized spins, revealing how spin correlations influence noise spectra and aligning with recent experimental observations.

Contribution

It introduces a model that accounts for spin-correlated scattering processes in shot noise, extending the Landauer-Büttiker formalism to include spin effects.

Findings

Both super- and sub-Poissonian shot noise are explained.

The model aligns with recent experimental data on magnetic adatoms.

Insights into noise spectroscopy of magnetic atoms are provided.

Abstract

We address the shot noise in the tunneling current through a localized spin, pertaining to recent experiments on magnetic adatoms and single molecular magnets. We show that both uncorrelated and spin-correlated scattering processes contribute vitally to the noise spectrum. The spin-correlated scattering processes provide an additional contribution to the Landauer-B\"uttiker shot noise expression, accounting for correlations between the tunneling electrons and the localized spin moment. By calculating the Fano factor, we show that both super- and sub-Poissonian shot noise can be described within our approach. Our theory provides transparent insights to noise spectroscopy, consistent with recent experiments using local probing techniques on magnetic atoms.