Investigation of the coupling asymmetries at double-slit interference experiments

TL;DR

This paper investigates phase anomalies in double-slit quantum dot experiments, emphasizing the role of electron-electron interactions and coupling asymmetries, supported by 3D numerical simulations of the potential and energy states.

Contribution

It provides a detailed numerical analysis of coupling asymmetries and their impact on phase changes in quantum dot interference experiments, supporting phenomenological models.

Findings

Certain energy levels are more strongly coupled to leads.

Electron-electron interactions are crucial for explaining phase anomalies.

Numerical simulations align with experimental observations.

Abstract

Double-slit experiments inferring the phase and the amplitude of the transmission coefficient performed at quantum dots (QD), in the Coulomb blockade regime, present anomalies at the phase changes depending on the number of electrons confined. This phase change cannot be explained if one neglects the electron-electron interactions. Here, we present our numerical results, which simulate the real sample geometry by solving the Poisson equation in 3D. The screened potential profile is used to obtain energy eigenstates and eigenvalues of the QD. We find that, certain energy levels are coupled to the leads stronger compared to others. Our results give strong support to the phenomenological models in the literature describing the charging of a QD and the abrupt phase changes.