Spectroscopy of Quantum-Dot Orbitals with In-Plane Magnetic Fields

TL;DR

This paper introduces a spectroscopy method using in-plane magnetic fields to precisely determine the 3D shape and orientation of quantum dot orbitals, aiding in understanding and manipulating quantum dot confinement.

Contribution

The study presents a novel in-plane magnetic field spectroscopy technique for detailed 3D orbital shape analysis of quantum dots, surpassing previous methods in precision and detail.

Findings

Extracted quantum dot orbital shapes with sub-nm accuracy.

Validated shape manipulation via gate voltages.

Quantified deviations from harmonic confinement.

Abstract

We show that in-plane-magnetic-field assisted spectroscopy allows extraction of the in-plane orientation and full 3D shape of the quantum mechanical orbitals of a single electron GaAs lateral quantum dot with sub-nm precision. The method is based on measuring orbital energies in a magnetic field with various strengths and orientations in the plane of the 2D electron gas. As a result, we deduce the microscopic quantum dot confinement potential landscape, and quantify the degree by which it differs from a harmonic oscillator potential. The spectroscopy is used to validate shape manipulation with gate voltages, agreeing with expectations from the gate layout. Our measurements demonstrate a versatile tool for quantum dots with one dominant axis of strong confinement.