Efficient polarization-entangled state compensation in quantum entanglement distribution

Area of Science:

• Quantum Information Science
• Quantum Optics
• Photonics

Background:

• Polarization-entangled photon pairs are crucial for quantum communication.
• Transmission through free-space or fiber links alters photon polarization states, degrading entanglement.
• Reconstructing the initial entangled state at the receiving end is essential.

Purpose of the Study:

• To develop an efficient compensation method for restoring polarization-entangled states.
• To demonstrate the feasibility of the proposed compensation technique experimentally.

Main Methods:

• Utilizing coincidence measurements of entangled photons.
• Implementing a unitary polarization transformation on a single optical link.
• Employing a set of three waveplates and one-step feedback for experimental demonstration.

Main Results:

• Successfully restored the initial polarization-entangled state between receiving ends.
• Demonstrated the feasibility of the compensation method through experimental implementation.
• Showcased the efficiency of the proposed technique for entanglement preservation.

Conclusions:

• The presented method provides an efficient way to compensate for polarization changes in quantum channels.
• This technology is directly applicable to quantum entanglement distribution and related applications.
• Preserving polarization-entangled states is vital for advancing quantum communication technologies.