Dimensionality reduction for closed-loop quantum gate calibration

TL;DR

This paper introduces a systematic method for reducing the dimensionality of control pulse parameters in quantum gate calibration, improving efficiency and robustness against various errors in experimental quantum computing.

Contribution

It presents a novel dimensionality reduction technique for high-dimensional quantum control pulses, enabling more efficient and robust gate calibration in quantum experiments.

Findings

Successfully calibrated a robust $X_{\pi/2}$ gate against amplitude and detuning errors.

Achieved calibration of a $X_{\pi/2}$ gate robust to spectator qubit errors.

Demonstrated improved calibration efficiency in high-dimensional parameter spaces.

Abstract

Numerical gate design typically makes use of high-dimensional parameterizations enabling sophisticated, highly expressive control pulses. Developing efficient experimental calibration methods for such gates is a long-standing challenge in quantum control, as on-device calibration requires the optimization of noisy experimental data over high-dimensional parameter spaces. To improve the efficiency of calibrations, we present a systematic method for reducing the dimensionality of the parameter space traversed in gate calibration, starting from an arbitrary high-dimensional pulse representation. We use this approach to design and calibrate an $X_{\pi/2}$ gate robust against amplitude and detuning errors, as well as an $X_{\pi/2}$ gate robust against coherent errors due to a spectator qubit.