A Continuous Variable Quantum Switch

TL;DR

This paper introduces a quantum switching architecture for continuous variable quantum information that supports multiple entanglement flows, utilizing a Max-Weight scheduling policy to optimize throughput in quantum networks.

Contribution

It presents the first quantum repeater switch design for continuous variable encodings supporting multiple communication flows with a throughput-optimized routing protocol.

Findings

Achievable bipartite entanglement request rate region demonstrated

Numerical results show stable support for multiple CV entanglement flows

Switch architecture enables efficient routing in CV quantum networks

Abstract

The continuous quadratures of a single mode of the light field present a promising avenue to encode quantum information. By virtue of the infinite dimensionality of the associated Hilbert space, quantum states of these continuous variables (CV) can enable higher communication rates compared to single photon-based qubit encodings. Quantum repeater protocols that are essential to extend the range of quantum communications at enhanced rates over direct transmission have also been recently proposed for CV quantum encodings. Here we present a quantum repeating switch for CV quantum encodings that caters to multiple communication flows. The architecture of the switch is based on quantum light sources, detectors, memories, and switching fabric, and the routing protocol is based on a Max-Weight scheduling policy that is throughput optimal. We present numerical results on an achievable bipartite entanglement request rate region for multiple CV entanglement flows that can be stably supported through the switch. We elucidate our results with the help of exemplary 3-flow networks.