Experimental distribution of entanglement with separable carriers

Area of Science:

• Quantum Information Science
• Quantum Networking
• Quantum Communication

Background:

• Quantum networking relies on distributing entanglement between nodes.
• Traditional methods often require direct entanglement transfer, limiting practical applications.
• Quantum discord is a more general measure of quantum correlation than entanglement.

Purpose of the Study:

• To demonstrate entanglement distribution without direct entanglement transfer.
• To investigate the use of separable carriers for entanglement generation.
• To assess the resilience of this method to environmental noise.

Main Methods:

• Experimental setup involving two communicating parties and three initially separable photonic qubits.
• Exchange of a carrier photon that remains unentangled with either party.
• Characterization of entanglement generated between the parties.

Main Results:

• Successful generation of entanglement between communicating parties using an unentangled carrier photon.
• Demonstration that entanglement gain is bounded by communicated quantum discord.
• Entanglement distribution via separable carriers shows resilience to noise.

Conclusions:

• Entanglement can be distributed across quantum networks without direct entanglement transfer.
• Separable carriers offer a viable and noise-resilient mechanism for quantum network entanglement.
• This method expands the possibilities for establishing quantum correlations in noisy environments.