Abstract: Suppressing decoherence and errors due to environmental noise is
essential for quantum information processing and other quantum
technologies. Accurate characterization of environmental noise is an
important step towards this goal, as it will enable the design of
control protocols tailored to specific characteristics of the noise.
Because their performance is highly sensitive to spectral features of
environmental noise, dynamical decoupling sequences can serve as
"probes" of noisy environments. In recent years, several methods of
noise spectroscopy through open­ loop quantum control have been
proposed and demonstrated experimentally. However, this effort has
largely been confined to the case of classical, Gaussian phase noise.
We introduce an open loop quantum control protocol for characterizing
non­-Gaussian dephasing on a single qubit, which is applicable to
stationary noise- both classical and quantum. For a representative
classical model as well as the linear quantum spin boson model, we
reconstruct the spectra associated with the leading higher­ order
cumulants of the noise, absent in the Gaussian case. In the Gaussian
regime, our protocol improves upon existing techniques by
reconstructing the spectrum over a larger range in frequency space.