Quantum technology with a spin-photon architecture for thousand-qubit chipsets at telecom wavelengths

Introduction

Scalability is one of the core challenges of present-day quantum technology. While many promising demonstrations have been performed at the level of tens of qubits, a vast leap will be required to create systems with the many thousands of physical qubits with the outstanding quality needed for the achievement of quantum computational advantage and high-bandwidth quantum communication.

Emerging Platforms

Spin centres in silicon carbide are an emerging platform for quantum information and communication. Some of these systems have long spin lifetimes and strong optical transitions in the near-infrared optical spectrum. This optical band is advantageous for:

• Strong photonic enhancement
• Interfacing with low-loss waveguide and fiber networks

These defects possess electronic spins for photonic links and nuclear spins for quantum information storage. The multilevel systems furthermore offer a platform for novel, resource-efficient quantum information methods based on high-dimensional encoding.

Material Advantages

Silicon carbide is a highly developed material platform, offering:

1. Extremely high purity
2. Transparency
3. Compatibility with eminently scalable semiconductor processing methods

Project Goals

In QuSPARC, we will develop and demonstrate wafer-scale processes to create thousands of near-identical qubit sites with spin control on a SiC wafer, and with optical enhancement interfaces using optical micro-resonators of extremely high quality.

Methodology

We will determine optimized methods for the control and readout of selected spin centres in SiC towards fault-tolerant implementations. Based on these insights, we will demonstrate:

• High-fidelity spin initialization
• Spin measurement
• Spin-photon entanglement
• Connectivity between sites on these microchips

Conclusion

QuSPARC will thereby achieve a disruptive step change in the development of scalable quantum information devices, leading the race towards the creation of million-qubit systems for high-performance quantum technology.