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arXiv · 1512.01575

Qubit noise spectroscopy for non-Gaussian dephasing environments

Leigh M. Norris·Gerardo A. Paz-Silva·Lorenza Viola
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Abstract

We introduce open-loop quantum control protocols for characterizing the spectral properties of non-Gaussian noise, applicable to both classical and quantum dephasing environments. The basic idea is to engineer a multi-dimensional frequency comb via repetition of suitably designed pulse sequences, through which the desired high-order noise spectra may be related to observable properties of the qubit probe. We prove that access to a high time resolution is key to achieve spectral reconstruction over an extended bandwidth, overcoming limitations of existing schemes. Non-Gaussian spectroscopy is demonstrated for a classical noise model describing quadratic dephasing at an optimal point, as well as a quantum spin-boson model out of equilibrium. In both cases, we obtain spectral reconstructions that accurately predict the qubit dynamics in the non-Gaussian regime.

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Leigh M. Norris, Gerardo A. Paz-Silva, Lorenza Viola. 2015-12-04. Qubit noise spectroscopy for non-Gaussian dephasing environments. https://doi.org/10.1103/physrevlett.116.150503

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