Quantum entanglement protocol for a quantum interconnection device

A method for establishing, using a quantum interconnection device, quantum entanglement between a first quantum device and a second quantum device, the method comprising:

• receiving, at the quantum interconnection device, a first entangled photon, wherein the first entangled photon is entangled with a first communication qubit of the first quantum device;
• performing a heralded, quantum information storage operation between the first entangled photon and a first memory qubit of the quantum interconnection device to transfer the quantum information to the first memory qubit, and such that quantum entanglement is extended to between the first communication qubit of the first quantum device and the first memory qubit of the quantum interconnection device;
• performing a local gate operation to transfer the quantum information to a second memory qubit;
• and
• responsive to receiving a second heralding signal that indicates that a separate quantum entanglement has been extended to between a first communication qubit of the second quantum device and the first memory qubit of the quantum interconnection device,
• performing a local, deterministic gate operation between the first and the second memory qubits, such that quantum entanglement is established between the first communication qubit of the first quantum device and the first communication qubit of the second quantum device.

A system, comprising:

• a quantum interconnection device, configured to execute a quantum entanglement protocol to provide quantum entanglement between a first quantum device and a second quantum device, wherein the quantum interconnection device comprises:
• optically active quantum memories, configured to store quantum information;
• and
• optical pathways that enable respective ones of the optically active quantum memories to be connected to single photon detectors;
• and
• a classical processor, configured to cause the quantum entanglement protocol to be executed, wherein, to cause the quantum entanglement protocol to be executed, the classical processor is further configured to:
• cause a heralded, quantum information storage operation to be performed between respective qubits of the optically active quantum memories;
• and
• responsive to reception of heralding signals via the single photon detectors,
• cause a local, deterministic gate operation to be performed between the respective qubits of the optically active quantum memories;
• or
• cause an optically-mediated, heralded quantum entanglement operation between at least the respective qubits of the optically active quantum memories.