Qubits based on solid-state spins are well suited for the construction of quantum computers due to their potential for miniaturisation and scalability. However, targeted and reproducible production with defined properties remains a challenge. Within the framework of the Quantum Computing Initiative (QCI), the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is developing two auxiliary technologies: a universal qualification system for solid-state spin qubits and a process for the reproducible production of nitrogen-vacancy (NV) centres in diamond. In this way, we support both the development of our own quantum computers based on NV centres and the wider quantum computing ecosystem.
Importance for Germany
Quantum computers based on NV centres are particularly important within the German quantum computing ecosystem. However, because NV centres also enable various other quantum technologies in addition to quantum computing, it is crucial that the associated supply chains are also upgraded. The manufacturing processes and characterisation systems developed within the framework of the DLR QCI thus also support companies in the field of quantum sensors, quantum memories and quantum networks. In this way, the entire ecosystem necessary to produce NV centres in diamond can be created in Germany.
Spin-enabling technologies in the DLR QCI
These industrial contracts focus on the development of a universal qualification system for solid-state spin qubits and the reproducible production of NV centres in diamond to develop diamond-based quantum computers. This will directly benefit the companies we commission to develop quantum computers with NV centres. The work on these spin-enabling technologies takes place at the DLR Innovation Centre in Ulm. There, they benefit from many advantages of the location, such as the proximity to the Institute for Quantum Optics at the University of Ulm, a leading institute in the field of research on vacancies in diamond.
DLR has awarded two contracts. The first contract concerns the construction and operation of a modular, customisable qualification system for solid-state spin qubits. The system targets individual NV centres in diamond and other solid-state defects using lasers, microwaves and radio frequencies. The characterisation is carried out at room temperature and cryogenic temperatures to be able to represent the properties of the spin qubits as accurately as possible.
The second contract addresses the development of a process for the reproducible production of quantum hardware components based on NV centres. For this purpose, diamond layers are built up in a controlled process, into which nitrogen ions are then integrated in a targeted manner. The diamond is then heated considerably, whereby it recovers its lattice structure, which was disturbed by the integration of the nitrogen ions. This is how high-quality NV centres are created. This process requires specific equipment, which is developed and built in our laboratories at the DLR Innovation Centre in Ulm and optimised during operation.