Qubits are the processing units of quantum computers. They can be created in various different ways. One option is the creation of solid-state spin qubits in materials such as diamonds, in which qubits get stuck in defects that are specifically inserted into the structure of diamond crystals. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) has now awarded two contracts related to this activity as part of the DLR Quantum Computing Initiative (QCI). Over the next three and a half years, Advanced Quantum from Allmersbach (Baden-Württemberg) will develop quality assurance procedures to accompany the creation of the modified diamond structures and other solid bodies that are suitable for qubits. Diatope from Ummendorf (Baden-Württemberg) produces high-quality diamond layers with nitrogen-vacancy (NV) centres. The contracts amount to a total of 13 million euros.
„Start-ups benefit particularly from the DLR Quantum Computing Initiative; the young companies are effectively integrated into the development of a commercial ecosystem for quantum computing. This can lead to an industrial base that is internationally competitive and strengthens Germany as a technological location in this key technology.”Dr. Anna Christmann, Commissioner of the German Federal Ministry for Economic Affairs and Climate Action (BMWK) for the Digital Economy and Start-ups.
“Nitrogen-vacancy centres in diamond are considered particularly suitable spin qubits for use in the construction of quantum computers,” says Dr. Robert Axmann, Head of the DLR Quantum Computing Initiative. “To continue to make technological progress in this field, it is vital to have these spin qubits available in high quality and sufficient number. That is what these contracts aim to achieve.” One of the advantages of diamond-based qubits is that they operate at room temperature. Superconducting systems, which are also solids, are comparatively well developed, but they require extremely low operating temperatures. “For quantum computing, it is still unclear which systems scale well – in other words, allow for higher numbers of qubits – and eliminate or make it possible to correct errors. That makes it all the more important to investigate multiple qubit technologies,” adds Axmann.
Manufacturers reap mutual benefits
The two start-ups support and accelerate the further development of quantum computers based on nitrogen-vacancy (NV) centres in diamond. They also ensure that the manufactured qubits have consistent properties. The awarded contracts will specifically develop and expand the ecosystem for the field of quantum computers based on solid-state spins and are closely interlinked with the contracts awarded for the construction of quantum computers based on NV centres.
Advanced Quantum is working on quality assurance procedures for solid-state spin qubits. The defects in diamonds and other materials will be controlled with laser beams, microwaves and radio frequencies. In order to represent the properties of the spin qubits in as much detail as possible, Advanced Quantum also carries out an analysis of the samples at cryogenic (ultra-low) temperatures.
Diatope produces quantum hardware based on NV centres. Diatope grows ultra-pure diamond layers in a controlled process and then implants nitrogen ions into the crystal structure. The diamonds are then heated. As a result, they regain their lattice structure, which was disrupted by the incorporation of the nitrogen ion. Diatope builds special systems to carry out these individual processes and then works to optimise their operation.
„These contracts have been awarded with close collaboration in mind, not just between the two projects, but also with other industry partners and DLR institutes involved in the DLR Quantum Computing Initiative. Everyone involved will benefit, and we will see advancements in the quantum computing ecosystem in Germany as a whole.”Dr. Karla Loida, Project Lead Hardware for the DLR Quantum Computing Initiative
Beide Start-ups nutzen Labore im DLR-Innovationszentrum Ulm. Dort und im DLR-Innovationszentrum Hamburg bestehen Synergien mit den DLR-Instituten und weiteren Projekten in der DLR Quantencomputing-Initiative.