Cryostat Wiring Bottleneck: 2D Conductance Ladder

This is the 2D counterpart to the 3D Cryostat Wiring Bottleneck simulator, computed independently from real cryogenic material physics rather than a flattened render of the 3D scene. Each of the four stage-to-stage wire segments in a five-stage dilution refrigerator gets its own conducted heat load, derived by numerically integrating a temperature-dependent thermal-conductivity model for stainless-steel and superconducting-NbTi wiring across that segment's real temperature span — not looked up from a static table. The main view draws a thermal ladder diagram showing every segment's load against its refrigeration budget, and a lower curve plots the Bose–Einstein thermal-photon occupation of the qubit readout resonator across a temperature sweep, with the current mixing-chamber operating point marked live. Adjust qubit count, coax lines per qubit, wiring material and frequency-multiplexed readout to see exactly where the wiring bottleneck bites.