A crucial requirement for large-scale quantum information processing will be the development of modular quantum processors capable of transmitting quantum information between qubits housed at different nodes.
In this talk, I will describe a strategy for generating “which-path” entanglement between a qubit and a light pulse [1].The resulting qubit—which-path entangled state can be used for distributing entanglement between nodes in a quantum network, or for achieving optimal quantum-enhanced phase estimation in an interferometer using phase sensitive (rather than photon-number-resolving) measurements [2]. Finally, I will also describe strategies for performing long-range "flying-cat" parity checks of distant stationary qubits using conditional phase shifts on propagating light pulses [3]. This could allow for the implementation of distributed fault-tolerant quantum computing, or for the measurement based preparation of entangled resource states for quantum communication protocols.
[1] Z. M. McIntyre and W. A. Coish, Phys. Rev. Lett. 132, 093603 (2024)
[2] Z. M. McIntyre and W. A. Coish, arXiv:2405.13265
[3] Z. M. McIntyre and W. A. Coish, Phys. Rev. Research 6, 023247 (2024)
