High-Order Qubit Dephasing at Sweet Spots by Non-Gaussian Fluctuators: Symmetry Breaking and Floquet Protection
Ziwen Huang, Xinyuan You, Uğur Alyanak, Alexander V. Romanenko, Anna Grassellino, Shaojiang Zhu · Physical Review Applied · 2022
The understanding and characterization of realistic noise are critical for assessing and reducing errors in qubits, but theoretical studies often overlook the different roles of Gaussian and non-Gaussian noise in reducing qubit coherence. The authors employ two theoretical approaches to inspect such differences in solid-state qubits, and find a symmetry-breaking effect that is unique to non-Gaussian noise and can be detected experimentally. They also propose a protocol that can significantly increase the coherence time. These findings provide simple yet powerful tools for detecting non-Gaussian noise as well as mitigating its detrimental effect on the qubits.