Machine learning enables completely automatic tuning of a quantum device faster than human experts
This work addresses scalability bottlenecks in quantum computing by enabling faster and more efficient tuning of quantum devices, though it is incremental as it builds on existing machine learning techniques for optimization.
The researchers tackled the challenge of device variability in semiconductor quantum devices by developing a statistical tuning algorithm that automatically navigates high-dimensional parameter spaces to find optimal operating conditions, achieving tuning in under 70 minutes and being approximately 180 times faster than a random search.
Device variability is a bottleneck for the scalability of semiconductor quantum devices. Increasing device control comes at the cost of a large parameter space that has to be explored in order to find the optimal operating conditions. We demonstrate a statistical tuning algorithm that navigates this entire parameter space, using just a few modelling assumptions, in the search for specific electron transport features. We focused on gate-defined quantum dot devices, demonstrating fully automated tuning of two different devices to double quantum dot regimes in an up to eight-dimensional gate voltage space. We considered a parameter space defined by the maximum range of each gate voltage in these devices, demonstrating expected tuning in under 70 minutes. This performance exceeded a human benchmark, although we recognise that there is room for improvement in the performance of both humans and machines. Our approach is approximately 180 times faster than a pure random search of the parameter space, and it is readily applicable to different material systems and device architectures. With an efficient navigation of the gate voltage space we are able to give a quantitative measurement of device variability, from one device to another and after a thermal cycle of a device. This is a key demonstration of the use of machine learning techniques to explore and optimise the parameter space of quantum devices and overcome the challenge of device variability.