High-Fidelity Quantum Control by Polychromatic Pulse Trains

Area of Science:

• Quantum Information Science
• Quantum Control Engineering
• Superconducting Quantum Computing

Background:

• Precise control of quantum systems is crucial for advancing quantum technologies.
• Existing quantum control methods often face limitations in robustness or sensitivity.
• Developing flexible and accurate control techniques is essential for scalable quantum computing and sensing.

Purpose of the Study:

• To introduce and validate a novel quantum control technique utilizing polychromatic pulse trains.
• To demonstrate the generation of diverse excitation profiles (broadband, narrowband, passband) with high fidelity.
• To explore the application of this technique for robust quantum computing and sensitive quantum sensing.

Main Methods:

• Derivation of polychromatic pulse trains with varying carrier frequencies (detunings).
• Generation of target transition probabilities and excitation profiles.
• Experimental validation on IBM's superconducting quantum processors.

Main Results:

• Successful generation of high-fidelity excitation profiles, both robust and sensitive to experimental variations.
• Demonstrated excellent agreement between theoretical predictions and experimental outcomes.
• Showcased detuning as an effective control parameter comparable to pulse phase.

Conclusions:

• The polychromatic pulse train technique offers a flexible and accurate approach to quantum control.
• The method enhances robustness for quantum computing and sensitivity for quantum sensing.
• This technique provides new avenues for quantum control, particularly where phase manipulation is challenging.