Cyclic Depopulation of Edge States in a large Quantum Dot

TL;DR

This study explores magneto-transport in a large quantum dot, revealing non-cyclic depopulation of edge states and providing insights into their geometry through charge stability measurements.

Contribution

It presents the first detailed analysis of edge state depopulation in a large quantum dot using charge detection and a capacitive model.

Findings

Edge states are non-cyclically depopulated within the quantum dot.

Charge stability diagrams reveal the coupling of Landau levels.

Capacitive modeling explains the depopulation behavior.

Abstract

We investigate magneto-transport through a 1.6 \mu m wide quantum dot (QD) with adjacent charge detector, for different integer filling factors in the QD and constrictions. When this system is operated as a Fabry-P\'erot interferometer, transport is governed by a Coulomb blockade mechanism. In the tunneling regime, we can directly measure the charge stability diagram of two capacitively and tunnel coupled Landau levels. This situation has been investigated in direct transport, as well as in single electron counting. The edge states within the dot are non-cyclically depopulated, which can be explained by a simple capacitive model and allows to draw conclusions about the edge state geometry within the quantum dot.