Even within the field of superconducting qubits there are a wide variety of quantum processor architectures. Materials, processor layouts, and qubit type are some important ways in which quantum processors (QPUs) differ from one another. In recent years there has been a growing interest in also changing the processor dimensionality, finding creative ways to integrate low-loss three-dimensional structures into formerly planar devices. The goal is to employ these methods of 3D integration to scale up quantum processors for NISQ applications, by overcoming the major scalability limitations that are faced by the current state of the art 2D devices.
We are working towards the design and fabrication of a scalable 3D integrated QPU. Our project has four main stages: design and simulation to understand the benefits of 3D integration as well as any new problems it may present, development of the fabrication methods necessary for 3D integration, testing of 3D integrated QPUs to compare the performance and capabilities to existing 2D processors, and employing these devices and the benefits they offer to perform interesting experiments and quantum simulations.