EU to invest €3m in GeSi quantum project
The European Commission is investing in a groundbreaking quantum chip that will use Germanium-Silicon (GeSi) to combine light and electronics, promising faster, more efficient quantum computers.
Supported by the Quantum Flagship, the ONCHIPS consortium aims to lay the foundations for a new type of quantum hardware with advanced materials that have never been combined before.
Quantum computers are set to be exceptionally powerful tools for solving certain types of problems, like simulating molecules for drug discovery, optimising complex systems, or breaking encryption. However, researchers seeking to scale them up to the size face significant hurdles.
“One major issue of scalability is that qubits are often limited in their ability to interact with one another,” explains project coordinator Professor Floris Zwanenburg, full professor at the University of Twente’s MESA+ Institute for Nanotechnology. “As the number of qubits increases, effective communication between them becomes more complex.”
But Germanium-Silicon (GeSi) presents a viable solution to overcome these bottlenecks.
“We are combining spin qubits for computation and photonics for communication on a GeSi platform that is compatible with traditional CMOS manufacturing, which could be a total game-changer for scaling quantum computers. By combining spin qubits (electrons) with photonic communication (light), the chip bridges the gap between processing quantum information and transmitting it over long distances. This will significantly help us solve a major bottleneck in quantum scalability”, Zwanenburg said.
While GeSi has been used and studied for decades as a material system in applications like transistors in semiconductor physics, it has never been implemented in quantum computing. Scientists have worked with cubic GeSi for years and even built qubits using it, but this special, hexagonal light-emitting version of the material has never found its way into a real quantum computer – until now.
“Materials like GeSi can have different arrangements of their atoms under different conditions,” said Zwanenburg. “These arrangements dictate whether the material conducts electricity, emits light, or interacts with quantum particles. When we look at the atomic structure of ‘hexagonal GeSi’, the atoms do not appear in the usual “cubic” pattern. Instead, they have a six-sided, hexagonal, honeycomb-like arrangement.
“In this ‘hexagonal phase’, this special structure makes the material better at giving off light. The atomic structure means it is suitable for quantum applications and photonics, where controlling light is crucial for communication, computation, and storage.”
The ONCHIPS team want to make quantum chips cheaper, easier to make, and ready to roll off the production line.
“ONCHIPS takes a unique and interdisciplinary approach: we are integrating everything onto a single chip to reduce the size and complexity of the system, making it easier to scale up. All the components, such as the qubits, communication pathways, and supporting electronics, are integrated into a single piece of material,” said Zwanenburg.
The consortium hopes to bolster the EU’s ability to produce advanced quantum chips domestically and position the continent as a pioneer in scalable quantum systems.
Set to conclude in 2026, ONCHIPS brings together a a number of European organisations. Consortium partners include Universiteit Twente in the Netherlands, which coordinates the project, along with Technische Universiteit Eindhoven (Netherlands), Technische Universität München (Germany), Centre National de la Recherche Scientifique (CNRS) (France), Universität Konstanz (Germany), Budapesti Műszaki és Gazdaságtudományi Egyetem (Hungary), and the Dutch company Single Quantum BV.
