A Hybrid Rydberg Quantum Gate for Quantum Network

TL;DR

This paper proposes a hybrid quantum gate using Rydberg atoms to connect optical and microwave qubits, analyzing its fidelity under noise and discussing experimental feasibility for quantum networks.

Contribution

It introduces a novel Rydberg-atom based hybrid quantum CZ gate connecting optical and microwave qubits, with detailed noise analysis and feasibility discussion.

Findings

Fidelity degradation due to noise channels is quantitatively analyzed.

The protocol's feasibility within current technology is assessed.

Challenges for experimental implementation are identified.

Abstract

The high fidelity storage, distribution and processing of quantum information prefers qubits with different physical properties. Thus, hybrid quantum gates interfacing different types of qubits are essential for the realization of complex quantum network structures. A Rydberg-atom based physical quantum CZ gate is proposed to hybridly process the polarisation-encoded single-photon optical qubit and the "Schroedinger cat" microwave qubit. The degradation of the fidelity under the influence of various noise channels, such as microwave cavity loss, sponetanous emission of atom states, and non-adiabaticity effect, etc, has been analyised through detailed theoretical analysis by deriving input-output relation of qubit fields. The feasibility and the challenges of the protocol within current technology are also discussed by analysing the possible experimental parameter settings.