Single-step implementation of a multiple-target-qubit controlled phase gate without need of classical pulses

Area of Science:

• Quantum Information Science
• Quantum Computing
• Atomic Physics

Background:

• Multiqubit gates are essential for quantum computation.
• Previous methods often involve complex operations and are susceptible to decoherence.

Purpose of the Study:

• To propose a simplified and robust method for achieving a multiqubit phase gate.
• To reduce decoherence and operational complexity in quantum gate implementation.

Main Methods:

• Utilizing three-level quantum systems (qutrits) coupled to a cavity or resonator.
• Employing a single operational step and a virtual photon process.
• Implementing a controlled-phase gate where one qubit controls n target qubits.

Main Results:

• Achieved a multiqubit phase gate with a single operational step.
• Significantly reduced decoherence compared to previous proposals.
• Demonstrated operation time independence from the number of qubits.
• Eliminated the need for classical pulses and adjustments of system parameters.

Conclusions:

• The proposed method offers a greatly simplified and more robust approach to multiqubit phase gate implementation.
• This technique minimizes decoherence from cavity decay, enhancing quantum gate fidelity.
• The operational simplicity and robustness make it a promising candidate for scalable quantum computing architectures.