Quantum Noise Spectroscopy Informed Optimized Gates

In recent years, a number of quantum noise spectroscopy (QNS) protocols have been developed to characterize spatio-temporally correlated noise processes. Estimates of the noise power spectral density from QNS protocols are meant to inform optimized control protocols designed to mitigate noise while simultaneously implementing a particular quantum operation. While it is widely accepted that QNS should yield an added advantage to optimized control, there has yet to be an experimental demonstration of QNS-informed optimized control on a non-trivial gate. Here, we demonstrate the utility of QNS-informed control through the design of single qubit operations. Gates are optimized to tailor the frequency response of a fixed frequency transmon using the offline-optimization approach: Filter Gradient Ascent in Function Space (F-GRAFS) [arXiv: 2206.03504 (2022)]. We experimentally verify filter design via the injection of Schrodinger Wave Autoregressive Moving Average (SchWARMA) [Phys. Rev. Res. 4, 013081 (2022)] engineered noise. Controlled noise environments are further employed to evaluate optimized gate performance relative to “noise-uninformed” single qubit operations, and quantify robustness to model uncertainty within the F-GRAFS optimization. Our results convey the significance of noise-informed control and provide experimental insight into the interplay between characterization protocols and optimized control.