Assisted cloning of an unknown shared quantum state

Area of Science:

• Quantum Information Science
• Quantum Communication Networks

Background:

• Quantum cloning is essential for quantum information processing.
• Existing protocols often require trusted central nodes for quantum information transfer.

Purpose of the Study:

• To propose a novel, distributed quantum cloning protocol.
• To enable secure quantum information transfer without centralizing data.

Main Methods:

• Utilizing quantum teleportation (QT) with GHZ-type states.
• Implementing single-qubit projective and Z-basis measurements.
• Extending the protocol using non-maximally entangled states and generalized measurements (POVM, Bell-state measurement).

Main Results:

• Achieved quantum cloning of arbitrary unknown shared states.
• Successfully transferred quantum information among multiple senders and receivers.
• Demonstrated secure information relay without fully trusted nodes.

Conclusions:

• The proposed protocol offers a secure and distributed method for quantum state cloning and information transfer.
• The extended schemes enhance flexibility in quantum network design.
• Ensures no single participant has complete access to the information, improving security.