Robust hyperparallel photonic quantum entangling gate with cavity QED

Area of Science:

• Quantum Information Science
• Quantum Optics
• Solid-State Quantum Systems

Background:

• Diamond nitrogen vacancy (NV) centers are promising solid-state qubits.
• Optical cavities enhance light-matter interactions crucial for quantum gates.
• Cavity quantum electrodynamics (cQED) provides a framework for controlling quantum states.

Purpose of the Study:

• To present a robust hyperparallel photonic controlled-phase-flip gate.
• To utilize the balance condition in an optical cavity with diamond NV centers.
• To perform quantum entangling operations on a two-photon system across polarization and spatial modes.

Main Methods:

• Embedding a diamond nitrogen vacancy center within an optical cavity.
• Leveraging cavity quantum electrodynamics principles to achieve a balance condition.
• Implementing a photonic controlled-phase-flip gate utilizing polarization and spatial-mode degrees of freedom.

Main Results:

• A hyperparallel photonic controlled-phase-flip gate with near-unit fidelity was demonstrated.
• Efficient depression of noise from unequal reflection coefficients was achieved.
• The gate doubles quantum entangling operations synchronously, reducing resource consumption and photonic dissipation.

Conclusions:

• The balance condition in optical cavities enables robust quantum gate operations.
• This approach is feasible in both weak and strong coupling regimes.
• Experimental realization of high-fidelity quantum gates is facilitated by the balance condition.