Enhanced-generation of atom-photon entanglement by using FPGA-based feedback protocol

Area of Science:

• Quantum Information Science
• Atomic Physics
• Optical Engineering

Background:

• Entanglement between atomic excitations and photons is vital for quantum repeaters and networks.
• Existing methods face limitations in generation rates and efficiency.

Purpose of the Study:

• To develop and implement a feedback-loop algorithm for enhanced atom-photon entanglement generation.
• To significantly increase the rate of atom-photon entanglement production using atomic ensembles.

Main Methods:

• Utilized a field-programmable gate array (FPGA) to implement a feedback-loop algorithm.
• Measured the generation rate, Bell parameter, and fidelity of atom-photon entanglement.
• Compared performance with and without the feedback protocol at various storage times.

Main Results:

• Achieved a 21.6-fold increase in the atom-photon entanglement generation rate at 51 μs storage time.
• Reported generation rates of ~3190/s (1 μs) and ~2100/s (51 μs) at 1.65% excitation probability.
• Demonstrated a Bell parameter of 2.40 ± 0.02 and fidelity of 85.5% ± 0.6% at 1 μs storage time.

Conclusions:

• The FPGA-based feedback-loop algorithm effectively enhances atom-photon entanglement generation rates.
• The developed method is scalable and can be extended for multiplexing to further boost entanglement rates.
• This advancement is critical for the practical implementation of quantum repeaters and networks.