Manufacturing large-scale high-yield hybrid superconducting-semiconducting on-chip cryogenic switches*

We will present our latest progress in the development of quantum integrated circuits based on hybrid superconductor-semiconductor two-dimensional electron gas in InGaAs heterostructure. In particular, the design, nanofabrication, and cryogenic measurements of large-scale hybrid superconductor-semiconductor field-effect conductance switches with novel chip architectures will be discussed with a focus on their electronic response, switching (ON/OFF) statistics, quantum yield, and reproducibility. We demonstrate techniques for the successful fabrication of novel cryogenic gate voltage addressable nanoelectronics chips with negligible gate voltage leakage and with high switching response statistics, reproducibility rate, and quantum yields. We find that to make efficient cryogenic switches, the attention should especially be on the quality junction geometrical and interfacial parameters as the former influence the uniform switching voltages and the latter have a direct effect on the ON-OFF state conductance. The OFF state conductance is also a function of the quality oxide layers isolating the source-drain electrodes of hybrid junctions from split gate electrodes [1].  

[1] K Delfanazari et al., arXiv:2307.04355