Quantum materials

Quantum technology is set to revolutionise the way data is generated, processed and transmitted. It encompasses three main fields:

• Quantum sensors for high-resolution measurements unachievable using classical sensors;
• Quantum communication to secure the internet against the rising threats, including attacks assisted by quantum computers;
• Quantum computers capable of performing complex calculations faster and more efficiently than classical machines.

Scaling up quantum systems to market-ready solutions is challenged by the notorious sensitivity of quantum systems against their local environment. The Quantum Materials group addresses these issues through dedicated research on making materials “quantum-grade” and scalable.

Objectives

Within this context, the Quantum Materials group was established at the end of 2022 and focuses on developing semiconductor quantum hardware for quantum technologies.

The emphasis is on silicon carbide semiconductor (SiC), for which synergies with the high-power electronics industry pave the way for industrial-scale quantum-chip fabrication. Research extends existing fabrication methods to the generation of efficient quantum colour centres, nanofabrication of photonic integrated circuits (PICs), post-fabrication treatments to improve stability and spectral properties, and application-relevant quantum benchmarking. The group’s vision is to leverage silicon carbide quantum chips for next-gen applications, including quantum communication, quantum computing and quantum sensing.

Scope of expertise

To enable these technologies, the group has established expertise in the following areas:

• Efficient creation of quantum colour centres based on focused ion implantation and annealing techniques;
• Nanofabrication of photonic circuits based on in-house cleanroom capabilities;
• Software-enabled control of quantum systems;
• High-throughput characterization of colour centres at room-temperature and cryogenic temperatures.

Ongoing research targets further expand this expertise in:

• Development of a scalable semiconductor quantum hardware platform:
  • Novel wafer-scale nanofabrication methods for quantum photonic circuitry;
  • SiC-on-insulator bonding;
  • Large-scale fabrication of photonic quantum chips and direct bonding to fibre arrays;
  • High-fidelity control of spin-based quantum processors and memories for quantum communication tasks.
• Post-fabrication improvements of quantum hardware:
  • Surface charge passivation methods to reduce the environmental sensitivity of quantum systems;
  • Study of hybrid architectures combining SiC photonics with phase-change materials;
  • Direct and indirect Fermi-level control in photonic nanostructures to optimise the performance of quantum systems.
• Quantum technology applications:
  • Spin-photon interfaces for quantum communication;
  • Distributed quantum computing;
  • Quantum sensing.