Resource-efficient frame-based non-Gaussian quantum noise spectroscopy and optimized control

Many state-of-the art qubit devices are exposed to noise that is temporally correlated (“non-Markovian”) and non-Gaussian. Characterizing such noise in a way that is accurate and useful for predicting arbitrary controlled dynamics is challenging given finite control resources. A recently proposed formalism [1] leverages the notion of a “frame” to generalize transfer filter-function techniques beyond the frequency domain and overcome important limitations of existing approaches. Notably, by tying the choice of frame to the available control, a model-reduced representation of the open-system dynamics is obtained, allowing efficient noise characterization under experimental constraints. Within this general framework, we show how to achieve digital noise spectroscopy of non-Gaussian classical dephasing using a window frame. Focusing on random telegraph noise as a concrete example, we demonstrate how non-Gaussian noise spectroscopy can provide high-order control-adapted noise spectra for qubit dynamics prediction and noise-tailored decoupling design. We find that, depending on the operating parameter regime, control that is optimized based on non-Gaussian noise spectroscopy can substantially outperform standard Walsh decoupling sequences as well as control that is optimized based only on Gaussian noise spectroscopy.



[1] T. Chalermpusitarak, B. Tonekaboni, Y. Wang, L. M. Norris, L. Viola, and G. A. Paz-Silva, Phys. Rev. X Quantum 2, 030315 (2021).