Various architectures of quantum processors for the realisation of quantum computers are currently being researched internationally: from stored ions and superconducting resonators to defects in crystal structures. These approaches usually focus on the realisation of a monolithic quantum processor in a single apparatus. However, this poses several scalability problems in the long term: from the standardisation of interfaces, miniaturisation and automation in production, to the realisation of quantum processor networks. 

The OptoQuant project addresses these problems and 

• is developing the basis for a future standardisation of ion trap processors in order to standardise and accelerate the development and testing of processors by different users, 
• researches and realises ion traps with integrated optics based on modern semiconductor manufacturing processes in order to be able to mass produce ion traps with guaranteed high quality in the long term, and 
• lays the foundations for quantum computer networks and quantum communication based on ion traps. 

Current research efforts in other research groups are pursuing and extending the capabilities of ion trap-based processors from single to multiple processor zones to perform quantum operations in parallel. In addition, the first optical elements are being integrated into ion traps: traps are being developed based on the widely used CMOS technology, and optical waveguides are being integrated directly into the substrates. The problem with this approach is that the materials compatible with this fabrication strongly absorb the ultraviolet light required for many ion species, which limits scalability. OptoQuant's architecture explores and extends advanced methods from semiconductor manufacturing with multilayer production processes. This allows the use of quartz glass, which is transparent well into the UV range, solving the absorption problem described above. In addition, ultra-short laser pulses are used to "write" waveguides directly into the quartz glass with the aim of making them both single-mode and polarisation-maintaining - something that has not yet been demonstrated with these materials. 

A first milestone of the project is the realisation of single-mode and polarisation-maintaining waveguides in UV-compatible substrates. Based on these findings, the first ion traps will be produced that are compatible with industrial production on the one hand and enable multiple processor zones with the help of the integrated waveguides on the other. These manufacturing methods will be fed into a currently non-existent standardisation process that covers the supply chain from compatible materials, assembly and quality control based on standardised interfaces to the characterisation of the ion trap processor.