Cooperative quantum interface for noise mitigation in quantum networks

TL;DR

This paper introduces a cooperative quantum interface that combines converter and qubit functions into a single device, significantly improving noise suppression and entanglement fidelity for long-distance quantum networks.

Contribution

The proposed CQI integrates converter and qubit coupling, reducing loss and noise, and demonstrates exponential performance gains with multiple nodes, advancing quantum network technology.

Findings

Achieves two orders of magnitude improvement in entangled infidelity.

Reduces insertion loss and intermediate noise compared to traditional systems.

Provides an exponential performance advantage with increasing remote nodes.

Abstract

Quantum frequency converters that enable the interface between the itinerant photons and qubits are indispensable for realizing long-distance quantum network. However, the cascaded connection between converters and qubits usually brings additional insertion loss and intermediate noises. Here, we propose a cooperative quantum interface (CQI) that integrates the converter and qubit coupling into a single device for efficient long-distance entanglement generation. Compared to traditional cascaded systems, our scheme offers several advantages, including compactness, reduced insertion loss, and suppression of noise from intermediate modes. We prove the excellent performance over the separated devices by about two orders of magnitude for the entangled infidelity of two remote nodes. Moreover, we discuss an extended scheme for multiple remote nodes, revealing an exponential advantage in performance as the number of nodes increases. The cooperative effect is universal that can be further applied to multifunctional integrated quantum devices. This work opens up novel prospects for quantum networks, distributed quantum computing, and sensing.