KQCircuits: an open-source package for automating design of superconducting quantum processors

Superconducting circuits have gained significant importance in recent years due to their application to the field of quantum computing. The first step in the design of a superconducting quantum processors consists of accurately laying out the desired quantum circuits and connectivity into a lithography mask file. As the complexity of quantum processors grow, accurate design of the underlying superconducting circuit has become a significant challenge.



We present KQCircuits, a GPLv3-licensed tool developed at IQM Finland, that enables designing state-of-the-art quantum circuits and processors with relative ease, whilst reducing costly human errors. We demonstrate how large-scale quantum processors can be drawn parametrically and programmatically using built-in and custom components. Users can now design their routing wires using the KLayout user-interface, transitioning smoothly between coding and visual design. KQCircuits also incorporates finite-element simulations seamlessly into the software, establishing a complete and robust workflow. Moreover, through support for the open-source finite-element toolbox “Elmer” we drastically reduce the entry barrier for users who might not have access to proprietary software.



Our open-source design tools sharply reduce the learning-curve for new experimentalists, whilst providing highly flexible and reliable designs for experienced professionals in the industry. With KQCircuits, quantum engineers can quickly develop new experiments, whilst having the opportunity to contribute to the codebase and actively engage in the quantum community.