High-precision nonlocal temporal correlation identification of entangled photon pairs for quantum clock...

Area of Science:

• Quantum Information Science
• Quantum Optics
• Metrology

Background:

• High-precision nonlocal temporal correlation identification is essential for quantum information applications like remote time scale synchronization.
• Previous methods, using iterative fast Fourier transforms, had limited resolution and precision due to peak identification thresholds.

Purpose of the Study:

• To enhance the resolution and precision of nonlocal temporal correlation identification in entangled photon pairs.
• To overcome the limitations of existing algorithms for time offset measurement.

Main Methods:

• A modified direct cross-correlation extraction algorithm was developed.
• This new method bypasses the peak identification threshold limitations of previous algorithms.

Main Results:

• Achieved a flexible resolution down to 1 picosecond (ps), dependent on the time-tagging device's least significant bit resolution.
• Demonstrated sub-picosecond precision (0.72 ps) with an acquisition time of 4.5 seconds.
• Identified that precision is influenced by detector timing jitter, pair rate, and acquisition time.

Conclusions:

• The developed direct cross-correlation method significantly improves resolution and precision in nonlocal temporal correlation identification.
• This advancement provides a robust foundation for entanglement-based quantum clock synchronization, ranging, and communication applications.