Randomization of Pulse Phases for Unambiguous and Robust Quantum Sensing

Area of Science:

• Quantum Information Science
• Quantum Sensing
• Experimental Physics

Background:

• Quantum sensing relies on precise control of quantum systems.
• Errors from control pulses limit sensitivity and lead to false signals.
• Existing methods struggle to suppress multiple error types simultaneously.

Purpose of the Study:

• To develop a universal method for robust quantum sensing.
• To achieve unambiguous signal identification in quantum measurements.
• To suppress errors caused by pulse imperfections and finite pulse widths.

Main Methods:

• Theoretical development of a dynamical decoupling protocol.
• Experimental demonstration using a single nitrogen vacancy center in diamond.
• Randomization of control pulses to suppress spectral errors.
• Benchmarking against nonrandomized pulse sequences for nanoscale nuclear-spin sensing and ac magnetometry.

Main Results:

• Demonstrated a universal dynamical decoupling method for robust quantum sensing.
• Successfully suppressed spurious responses and signal distortion in measured spectra.
• Achieved unambiguous signal identification by mitigating two key error sources.
• Showcased enhanced performance in nanoscale nuclear-spin sensing and ac magnetometry.

Conclusions:

• The proposed method offers a universal approach to enhance quantum sensing robustness.
• Randomized control pulses effectively suppress critical errors, improving signal fidelity.
• This technique can be integrated with existing quantum sensing protocols for performance improvement.