Anisotropic magnetic field dependence of many-body enhanced electron tunnelling through a quantum dot

TL;DR

This study explores how magnetic fields influence electron tunneling through InAs quantum dots, revealing anisotropic effects and the role of quantum dot symmetry on electron interactions at very low temperatures.

Contribution

It demonstrates the anisotropic magnetic field dependence of electron tunneling and links this behavior to the symmetry of quantum dot eigenfunctions and electron-electron interactions.

Findings

Magnetic field enhances tunneling current at low temperatures.

Strong angular anisotropy observed when rotating magnetic field.

Lowered symmetry of QD eigenfunctions affects electron interactions.

Abstract

We investigate the effect of an applied magnetic field on resonant tunneling of electrons through the bound states of self-assembled InAs quantum dots (QDs) embedded within an (AlGa)As tunnel barrier. At low temperatures (no more than 2 K), a magnetic field B applied either parallel or perpendicular to the direction of current flow causes a significant enhancement of the tunnel current. For the latter field configuration, we observe a strong angular anisotropy of the enhanced current when B is rotated in the plane of the quantum dot layer. We attribute this behavior to the effect of the lowered symmetry of the QD eigenfunctions on the electron-electron interaction.