Rapid cryogenic characterization of 1,024 integrated silicon quantum dot devices

Abstract

As quantum processors grow in complexity, new challenges arise such as the management of device variability and the interface with supporting electronics. Spin qubits in silicon quantum dots can potentially address these challenges given their control fidelities and potential for compatibility with large-scale integration. Here we report the integration of 1,024 independent silicon quantum dot devices with on-chip digital and analogue electronics, all operating below 1 K. A high-frequency analogue multiplexer provides fast access to all devices with minimal electrical connections, allowing characteristic data across the quantum dot array to be acquired and analysed in under 10 min. This is achieved by leveraging radio-frequency reflectometry with state-of-the-art signal integrity, characterized by a typical signal-to-noise voltage ratio in excess of 75 for an integration time of 3.18 μs. We extract key quantum dot parameters by automated machine learning routines to assess quantum dot yield and understand the impact of device design. We find correlations between quantum dot parameters and room-temperature transistor behaviour that could be used as a proxy for in-line process monitoring.