Dipolar exchange quantum logic gate with polar molecules.

Area of Science:

• Quantum Information Science
• Atomic and Molecular Physics
• Quantum Computing

Background:

• Ultracold polar molecules offer unique advantages for quantum information processing due to their electric dipole moments.
• Implementing two-qubit gates is crucial for building scalable quantum computers.

Purpose of the Study:

• To propose a novel two-qubit gate design utilizing ultracold polar molecules.
• To investigate the feasibility and fidelity of an iSWAP gate implemented with sodium cesium (NaCs) molecules.

Main Methods:

• Utilizing nuclear spin states of NaCs molecules as qubits.
• Employing a rotationally excited state with rotation-hyperfine coupling to enable switchable electric dipolar interactions.
• Analyzing the full molecular Hamiltonian and considering various sources of error.

Main Results:

• Demonstrated a feasible iSWAP gate operation between two individually addressable NaCs molecules.
• Identified key error sources, including coupling to other molecular states and environmental factors.
• Projected a potential gate fidelity exceeding 99.99% under ideal conditions.

Conclusions:

• The proposed gate design offers a promising pathway for high-fidelity quantum operations with ultracold polar molecules.
• The system's insensitivity to external fields and potential for optical scaling are significant advantages.
• This work contributes to the development of scalable and robust quantum computing architectures.