One-dimensional quantum dot array integrated with charge sensors in an InAs nanowire

TL;DR

This paper demonstrates a controllable one-dimensional quintuple-quantum-dot array in an InAs nanowire with integrated charge sensors, enabling detailed charge configuration mapping and strong inter-dot interactions for quantum hardware applications.

Contribution

It introduces a fully tunable 1D quantum dot array with integrated charge sensors and virtual gates, advancing quantum device control and interaction strength in InAs nanowires.

Findings

Charge stability diagrams successfully mapped for all dots.

Individual energy levels controlled by virtual gates.

Strong inter-double-dot coupling confirmed by simulation.

Abstract

We report an experimental study of a one-dimensional quintuple-quantum-dot array integrated with two quantum dot charge sensors in an InAs nanowire. The device is studied by measuring double quantum dots formed consecutively in the array and corresponding charge stability diagrams are revealed with both direct current measurements and charge sensor signals. The one-dimensional quintuple-quantum-dot array are then tuned up and its charge configurations are fully mapped out with the two charge sensors. The energy level of each dot in the array can be controlled individually by using a compensated gate architecture (i.e., "virtual gate"). After that, four dots in the array are selected to form two double quantum dots and ultra strong inter-double-dot interaction is obtained. A theoretical simulation based on a 4-dimensional Hamiltonian confirms the strong coupling strength between the two double quantum dots. The highly controllable one-dimensional quantum dot array achieved in this work is expected to be valuable for employing InAs nanowires to construct advanced quantum hardware in the future.