Bidirectional multi-nodes quantum teleportation using discrete-time quantum walk.

Area of Science:

• Quantum Information Science
• Quantum Communication Networks
• Quantum Computing

Background:

• Traditional quantum teleportation is unidirectional, limiting simultaneous information exchange.
• Existing protocols require separate transmissions for each direction.
• Scalable and efficient bidirectional quantum communication is crucial for advanced quantum networks.

Purpose of the Study:

• To develop a novel technique for bidirectional quantum teleportation (BQT).
• To enable simultaneous quantum state transfer between two users within a single protocol.
• To analyze the fidelity and performance of BQT in realistic quantum network scenarios.

Main Methods:

• Encoding quantum information using non-orthogonal coherent states, converted to Schrödinger cat states.
• Utilizing discrete-time quantum walks with four distinct steps acting on a three-part quantum system.
• Deriving analytical formulas for teleportation fidelity using density matrix overlaps.
• Simulating large-scale quantum networks with realistic limitations using the SeQUeNCe discrete-event simulator.

Main Results:

• Achieved simultaneous, high-fidelity bidirectional quantum state transfer.
• Demonstrated BQT's effectiveness in high-capacity, large-scale network settings.
• Identified a greater resource overhead compared to unidirectional protocols.
• Evaluated quantum memory utilization, throughput, and end-to-end fidelity under various network conditions.

Conclusions:

• The proposed hybrid framework offers a scalable and analytically simple solution for next-generation quantum communication.
• BQT provides symmetric communication with strong fidelity, especially in demanding network environments.
• This approach integrates discrete-time quantum evolution with continuous-variable state encoding for enhanced quantum networks.