Demonstration of non-Markovian process characterisation and control on a quantum processor.

Area of Science:

• Quantum Computing
• Quantum Information Science
• Condensed Matter Physics

Background:

• Quantum computing fault-tolerance typically assumes uncorrelated (Markovian) environmental noise.
• Correlated (non-Markovian) noise is a significant hurdle for scaling quantum devices and has been difficult to characterize.
• Understanding and mitigating non-Markovian noise is essential for the advancement of quantum technology.

Purpose of the Study:

• To develop a novel framework for characterizing non-Markovian dynamics in quantum systems.
• To experimentally validate this framework on multi-qubit superconducting quantum devices.
• To demonstrate the framework's ability to predict device behavior beyond standard Markovian assumptions.

Main Methods:

• Development of a new theoretical framework for non-Markovian noise characterization.
• Experimental testing of the framework on multi-qubit superconducting quantum processors.
• Quantitative assessment of prediction accuracy using infidelity metrics.

Main Results:

• The developed framework accurately predicts the behavior of quantum devices affected by non-Markovian noise with an infidelity of 10^-3.
• The characterization technique enables superior quantum control over noisy processes.
• Effective decoupling from the non-Markovian environment leads to a significant extension of qubit coherence times.

Conclusions:

• The novel framework provides a robust method for characterizing non-Markovian noise in quantum systems.
• This technique is applicable to any controlled quantum device, offering a pathway to optimal operation.
• The results represent a significant advancement in noise reduction strategies for quantum computing.