Multiplexed communication over a high-speed quantum channel

TL;DR

This paper demonstrates that multiplexed quantum communication over a high-speed channel using a comb of vacuum squeezing has higher capacity per photon than broadband squeezing, with experimental validation of multiplexed transmission.

Contribution

It introduces a multiplexed quantum communication system supported by a vacuum squeezing comb and experimentally demonstrates its higher channel capacity and multiplexed communication capabilities.

Findings

Higher channel capacity per photon compared to broadband squeezing.

Successful time-resolved observation of vacuum squeezing comb teeth.

Experimental demonstration of multiplexed quantum communication.

Abstract

In quantum information systems it is of particular interest to consider the best way in which to use the non-classical resources consumed by that system. Quantum communication protocols are integral to quantum information systems and are amongst the most promising near-term applications of quantum information science. Here we show that a multiplexed, digital quantum communications system supported by comb of vacuum squeezing has a greater channel capacity per photon than a source of broadband squeezing with the same analogue bandwidth. We report on the time-resolved, simultaneous observation of the first dozen teeth in a 2.4 GHz comb of vacuum squeezing produced by a sub-threshold OPO, as required for such a quantum communications channel. We also demonstrate multiplexed communication on that channel.