Quantum computing based on superconducting integrated circuits is entering a pivotal phase, transitioning from fundamental research and development to early-stage technology scaling and industrial implementation. But still, scaling superconducting quantum computing beyond kilo-qubit levels represents a formidable challenge. Novel solutions are required such as overhead reduction and more integrated solutions in Semicon-inspired workflows. This, in turn, will lead to a renewed acceleration in superconducting quantum computing development. In this proceedings paper we address two major challenges on the path to quantum advantage: the wiring bottleneck and the test and characterization bottleneck. The wiring bottleneck arises because each qubit requires multiple dedicated control lines—up to three for current transmon-based processors—making large-scale integration difficult. Dense wiring increases thermal load and electromagnetic interference, which can degrade gate fidelities below the error-correction threshold. This creates a trade-off between scaling qubit numbers and maintaining qubit quality. The test and characterization bottleneck stems from the need to calibrate and benchmark every qubit individually, a process that scales poorly with qubit count. Unlike classical transistors, qubits require complex, quantum-level tuning, dramatically expanding the calibration parameter space. Without automation and accelerated testing, this will lead to a backlog of untested chips and limit throughput between fabrication and qualification.
Last et al. (Thu,) studied this question.