# Tuning the carrier tunneling in a single quantum dot with a magnetic field in Faraday geometry

## TL;DR

This study demonstrates that applying a magnetic field in Faraday geometry can significantly increase carrier tunneling times in a single quantum dot, primarily by shrinking the hole wave function and reducing tunneling at the edges.

## Contribution

It reveals a novel method to control carrier tunneling times in quantum dots using magnetic fields, highlighting the differential effects on electrons and holes.

## Key findings

- Hole tunneling time increases by nearly 60% at 9 T magnetic field.
- Magnetic field shrinks hole wave function, reducing tunneling at the lateral edges.
- Electron tunneling is less affected due to stronger localization at the QD center.

## Abstract

We report on an increase in the carrier tunneling time in a single quantum dot (QD) with a magnetic field in Faraday geometry using photocurrent spectroscopy. A nearly 60\% increase in hole tunneling time is observed with an applied magnetic field equal to 9 T. For a truncated pyramid QD, hole tunnels out faster at the lateral edge of the QD due to the reduced barrier height. The magnetic field in Faraday geometry shrinks the hole wave function at the center of QD plane, which weakens the tunneling at lateral edge and increases the average tunneling time. This mechanism also works for electron but the effect is smaller. The electron wave function is more localized at the center of the QD due to the uniform confining potential, therefore the relatively weak shrinkage caused by the magnetic field does not reduce the tunneling rate significantly.