Non-Gaussian noise spectroscopy with a superconducting qubit sensor

Area of Science:

• Quantum Information Science
• Quantum Control and Sensing

Background:

• Accurate noise characterization is crucial for quantum science, impacting decoherence modeling and quantum control.
• The common assumption of Gaussian noise statistics often fails, particularly with strong qubit-environment coupling or non-linear responses.

Purpose of the Study:

• To develop and experimentally validate a tool for characterizing non-Gaussian noise.
• To scrutinize the Gaussian noise assumption and identify non-Gaussian signatures in quantum systems.

Main Methods:

• Experimental validation of a quantum control protocol.
• Utilizing a superconducting qubit as a sensor.
• Reconstructing the higher-order spectrum of engineered non-Gaussian dephasing noise.

Main Results:

• Successful experimental demonstration of non-Gaussian noise spectroscopy.
• Reconstruction of both the noise spectrum and leading higher-order spectra.
• Validation of a quantum control protocol for noise characterization.

Conclusions:

• This work represents a significant advancement in quantum noise spectroscopy.
• The developed protocol is a key step towards a complete spectral estimation toolbox for quantum devices.
• Enables more accurate modeling of decoherence and optimized quantum control strategies.