Multi-terminal transport through a quantum dot in the Coulomb blockade regime

TL;DR

This paper investigates three-terminal tunneling in quantum dots within the Coulomb blockade regime, enabling precise measurement of state-lead coupling and revealing fluctuations due to wave function changes, advancing quantum electronic control.

Contribution

It introduces a method to quantitatively determine individual state couplings and observes their fluctuations, enhancing understanding of quantum dot-lead interactions.

Findings

Coupling strengths fluctuate with electron number and magnetic field.

Wave function shape changes influence tunneling coupling.

Control over dot-lead coupling is crucial for quantum electronics.

Abstract

Three terminal tunnelling experiments on quantum dots in the Coulomb blockade regime allow a quantitative determination of the coupling strength of individual quantum states to the leads. Exploiting this insight we have observed independent fluctuations of the coupling strengths as a function of electron number and magnetic field due to changes in the shape of the wave function in the dot. Such a detailed understanding and control of the dot-lead coupling can be extended to more complex systems such as coupled dots, and is essential for building functional quantum electronic systems.