Engineering cryogenic setups for 100-qubit scale superconducting circuit systems

TLDR

A wired, thermally optimized dilution refrigerator is essential for current and future solid‑state quantum processors. The study engineers an extensible cryogenic setup that minimizes heat loads while enabling rapid qubit control and readout. The authors review design criteria for qubit drive, flux, and output lines in superconducting circuits, detailing each line type. Measurements of passive heat loads from stainless steel and NbTi coaxial cables and active loads from signal dissipation confirm the robustness of the thermal anchoring concept, underscoring its importance for managing the heat budget of future large‑scale superconducting quantum computers.

Abstract

A robust cryogenic infrastructure in form of a wired, thermally optimized dilution refrigerator is essential for present and future solid-state based quantum processors. Here, we engineer an extensible cryogenic setup, which minimizes passive and active heat loads, while guaranteeing rapid qubit control and readout. We review design criteria for qubit drive lines, flux lines, and output lines used in typical experiments with superconducting circuits and describe each type of line in detail. The passive heat load of stainless steel and NbTi coaxial cables and the active load due to signal dissipation are measured, validating our robust and extensible concept for thermal anchoring of attenuators, cables, and other microwave components. Our results are important for managing the heat budget of future large-scale quantum computers based on superconducting circuits.