Taming Recoil Effect in Cavity-Assisted Quantum Interconnects

TL;DR

This paper develops an analytical model to evaluate and mitigate motion-induced infidelity in remote entanglement protocols for trapped-atom qubits, crucial for advancing high-fidelity quantum networks.

Contribution

It introduces a versatile analytical model applicable to various photonic encodings and motional states, guiding optimal operating regimes for quantum networking.

Findings

Operating in the bad-cavity regime reduces recoil effects.

Near-ground-state cooling below 1 motional quantum minimizes infidelity.

Detection time filtering mitigates finite temperature effects.

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, 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 operating in the bad-cavity regime with cavity decay rate exceeding 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 towards fault-tolerant quantum networking with scalable trapped-atom qubit systems.