Submicrosecond entangling gate between trapped ions via Rydberg interaction

Area of Science:

• Quantum Information Science
• Atomic Physics
• Quantum Computing

Background:

• Trapped ions offer precise control for quantum entanglement but are limited by slow gate speeds.
• Fast entanglement gates are crucial for scaling quantum computers beyond classical limits.
• Rydberg atoms and polar molecules enable faster gates but lack stable confinement.

Purpose of the Study:

• To develop a faster quantum entanglement gate for large ion crystals.
• To combine the benefits of trapped ions and strong dipole-dipole interactions.
• To significantly accelerate trapped-ion quantum computers and simulators.

Main Methods:

• Implemented a two-ion entangling gate utilizing the strong dipolar interaction between trapped Rydberg ions.
• Achieved a gate time of 700 nanoseconds.
• Analyzed sources of gate error and predicted performance in larger systems.

Main Results:

• Successfully produced a Bell state with 78% fidelity using the new gate.
• Identified gate error sources and predicted a total error below 0.2% for achievable parameters.
• Predicted a gate error of approximately 10^-4 in a 100-ion crystal, with minimal motional mode coupling.

Conclusions:

• The novel Rydberg ion gate offers a substantial speedup for trapped-ion quantum computation.
• This method addresses the challenge of fast entanglement in large ion crystals.
• The approach promises to significantly enhance the scalability and performance of quantum computers and simulators.