A Graphene Quantum Dot with a Single Electron Transistor as Integrated Charge Sensor

TL;DR

This paper presents a graphene-based quantum dot integrated with a single electron transistor acting as a highly sensitive charge sensor, enabling detection of quantum states even with minimal current flow, advancing solid-state qubit development.

Contribution

The authors developed a novel etching process to fabricate an integrated graphene quantum dot and charge sensor, demonstrating high charge sensitivity and potential for quantum computing applications.

Findings

High charge sensitivity of the detector enables probing Coulomb diamonds and excited states.

The integrated device detects quantum states with minimal current, surpassing conventional methods.

Potential application as a building block for solid-state qubits in a nuclear-spin-free environment.

Abstract

We have developed an etching process to fabricate a quantum dot and a nearby single electron transistor as a charge detector in a single layer graphene. The high charge sensitivity of the detector is used to probe Coulomb diamonds as well as excited spectrum in the dot, even in the regime where the current through the quantum dot is too small to be measured by conventional transport means. The graphene based quantum dot and integrated charge sensor serve as an essential building block to form a solid-state qubit in a nuclear-spin-free quantum world.