Taming the Recoil Effect in Cavity-Assisted Quantum Interconnects

Abstract

Photon recoil is one of the fundamental limitations for high-fidelity control of trapped-atom qubits such as neutral atoms and trapped ions. In this work, we derive an analytical model for efficiently evaluating the motion-induced infidelity in remote entanglement generation protocols. Our model is applicable for various photonic qubit encodings, such as polarization, time-bin, and frequency encodings, and with arbitrary initial motional states, thus providing a crucial theoretical tool for realizing high-fidelity quantum networking. For the case of tweezer-trapped neutral atoms, our results indicate that operation in the bad-cavity regime with cavity decay rate exceeding the atom-photon coupling rate and near-ground-state cooling with motional quanta below 1 are desired to suppress the motion-induced infidelity sufficiently below the 1% level required for efficient quantum networking. Finite-temperature effects can be mitigated efficiently by detection time filtering at the moderate cost of success probability and network speed. These results extend the understanding of infidelity sources in remote entanglement generation protocols, establishing a concrete path toward fault-tolerant quantum networking with scalable trapped-atom qubit systems.