Non-Gaussian Noise Spectroscopy With Superconducting Qubits. Part 1: Theory.*

Non-Gaussian noise can play an important role in qubit decoherence, for example in the presence of two-level fluctuators or in environments far from thermal equilibrium. While there has been substantial experimental progress in characterizing Gaussian noise, non-Gaussian noise spectroscopy has yet to be experimentally implemented. This task is essential for designing robust control and error correction for realistic noisy environments. To accomplish this, a non-Gaussian noise characterization method based on dynamical decoupling was introduced in Ref. [1]. Before using these protocols on native noise, it is important to assess them with engineered non-Gaussian noise. In this talk, we theoretically describe how to benchmark this method in realistic superconducting qubit systems like the transmon. We also report on progress toward characterizing native non-Gaussian sources of noise in these systems.
[1] Norris et al. Phys. Rev. Lett. 116, 150503 (2016)