Modeling and Simulation of Realistic Multilayer Devices in Superconducting Quantum Electronics

In this work, we introduce a comprehensive numerical framework developed to model three-dimensional multilayer superconducting devices, with a particular emphasis on nanobridge junctions and coplanar waveguide structures. In contrast to conventional modeling approaches that rely on simplified geometries or restrict the number of materials involved, our method captures the full physical layout and material complexity of multilayer superconducting architectures. This enables a more faithful representation of realistic device behavior and offers researchers a flexible tool for the design and optimization of next-generation quantum circuits.

Our model allows for the precise calculation of critical currents, current–phase relationships, and energy gaps wherever these parameters play a defining role. To ensure reliability, we benchmark our simulations against experimental and published reference data, demonstrating strong agreement across a variety of material and geometric configurations.

The results reveal that employing multilayer superconducting films provides enhanced control over key device parameters, enabling engineers to tune circuit performance with greater precision. In the case of nanobridge junctions, the multilayer approach yields a marked increase in qubit anharmonicity relative to comparable monolayer designs—an effect that directly contributes to improved qubit isolation, reduced decoherence, and higher operational fidelity. Likewise, in coated multilayer microwave circuits, the model facilitates an in-depth exploration of the proximity effect and its influence on kinetic inductance, offering valuable insight into how layered superconductors can be engineered for optimal performance in superconducting quantum technologies.

Overall, this work establishes a numerically rigorous and physically realistic modeling platform for multilayer superconducting quantum electronic circuits, bridging the gap between theoretical prediction and experimental device design.