A general and modular approach to solid-state integration and readout of zero-dimensional quantum systems

TL;DR

This paper introduces a scalable, all-electrical readout method for zero-dimensional quantum states in solid-state systems, using layered heterostructures of graphene and hBN to enable spectroscopy and integration with quantum technologies.

Contribution

It presents a modular, general approach for solid-state quantum system readout that does not depend on optical methods, demonstrated with point defects and molecular qubits.

Findings

Successful electronic tunneling spectroscopy of point defects in hBN.

Demonstration of molecular qubit VOPc readout.

Potential for scalable integration of quantum systems.

Abstract

Here, we present an all-electrical readout mechanism for quasi-0D quantum states (0D-QS) such as point defects, adatoms and molecules, that is modular and general, providing an approach that is amenable to scaling and integration with other solid-state quantum technologies. Our approach relies on the crea-tion of high-quality tunnel junctions via the mechanical exfoliation and stacking of multi-layer gra-phene (MLG) and hexagonal boron nitride (hBN) to encapsulate the target system in an MLG/hBN/0D-QS/hBN/MLG heterostructure. This structure allows for all-electronic spectroscopy and readout of candidate systems through a combination of coulomb and spin-blockade. As a proof of principle, we demonstrate electronic tunneling spectroscopy of point defects in hBN and the molecular qubit vanadyl phthalocyanine (VOPc). Our approach demonstrates a new pathway for the incorporation of molecules and atomic defects into solid-state quantum devices and circuits along with a readout scheme that does not rely on highly-constrained optical processes for photonic readout.