Changes in the Magnetization of a Double Quantum Dot

TL;DR

This paper measures how magnetization changes in a double quantum dot due to electron tunneling, revealing complex behavior and chaotic energy state motion with implications for quantum systems.

Contribution

It provides the first detailed measurement of magnetization changes in a double quantum dot and compares experimental results with numerical and semiclassical models.

Findings

Magnetization exhibits wiggles as a function of magnetic field.

Observed energy spectrum crossings and anti-crossings.

Results align with numerical calculations but differ from semiclassical estimates.

Abstract

From accurate measurements of the energy states in a double quantum dot we deduce the change in magnetization due to single electron tunneling. As a function of magnetic field we observe crossings and anti-crossings in the energy spectrum. The change in magnetization exhibits wiggles as a function of magnetic field with maximum values of a few effective Bohr magnetons in GaAs. These wiggles are a measure of the chaotic motion of the discrete energy states versus magnetic field. Our results show good agreement with a numeric calculation but deviate significantly from semiclassical estimates.