Scaling superconducting qubits past 150

StateVector

Over the weekend I was messing around with my small superconducting qubit test rig and tried scaling up a basic error-corrected circuit beyond 150 qubits to check when crosstalk would take over. The readout fidelity fell off quicker than expected after adding more control lines, and changing the fab process didn’t help with the thermal noise like I thought it would. I’m wondering whether spin qubits might avoid this issue or if there’s a calibration step I’m overlooking that could sort it out.

qxplorer

Tried scaling my own test setup a couple years ago and watched the same fidelity cliff hit once the control lines stacked up, even after swapping processes. Spin qubits could sidestep some of that thermal noise, yeah, but I’d check your calibration on the new lines first before switching tech. Anyone else run into this exact crossover point?