Controlling shot noise in double-barrier magnetic tunnel junctions

TL;DR

This paper investigates how magnetic configuration and barrier asymmetry influence shot noise in double-barrier magnetic tunnel junctions, providing a theoretical model that explains experimental results and highlights potential for magnetic noise control in spintronics.

Contribution

The study introduces a theoretical model that accounts for shot noise behavior in magnetic tunnel junctions, considering spin relaxation and barrier asymmetry, aligning with experimental data.

Findings

Shot noise depends on magnetic configuration and barrier asymmetry.

Quantum well states cause conductance and shot noise enhancement at higher voltages.

The model accurately explains shot noise behavior below 0.5V.

Abstract

We demonstrate that shot noise in Fe/MgO/Fe/MgO/Fe double-barrier magnetic tunnel junctions is determined by the relative magnetic configuration of the junction and also by the asymmetry of the barriers. The proposed theoretical model, based on sequential tunneling through the system and including spin relaxation, successfully accounts for the experimental observations for bias voltages below 0.5V, where the influence of quantum well states is negligible. A weak enhancement of conductance and shot noise, observed at some voltages (especially above 0.5V), indicates the formation of quantum well states in the middle magnetic layer. The observed results open up new perspectives for a reliable magnetic control of the most fundamental noise in spintronic structures.