Multilayer Microwave Integrated Quantum Circuits*

Superconducting circuits are a promising candidate for a quantum computing architecture. However, in order to construct a universal fault-tolerant quantum computer, the number of circuit elements used needs to be much greater than what is currently attained. Simply scaling up current technologies faces several challenges. For planar-layout circuits, increasing the number of elements presents increased cross-talk as well as difficulties with providing connectivity to inner elements. In this talk, we discuss an architecture for scaling up circuits while avoiding these challenges via the 3D layout of circuits. For example, lithographically-produced superconducting micromachined cavities provide isolation between the different parts of the circuit, and can additionally be harnessed as high-Q resonators for storage. The added benefits of mass-producibility and lithographic precision provided by the design help it avoid additional difficulties likely to arise in attempting to create larger circuits. This talk will expound on our vision and provide updates with some recent results.