Quantum-repeater-enabled networks (Conference Presentation)

William J. Munro, Kae Nemoto

We have seen remarkable progress made over the last decade in the realization and exploitation of small-scale quantum communication technologies. The community is now at the stage where we need to consider how quantum repeaters and their associated networks are efficiently designed and implemented. This first requires us to define what a quantum repeater actually is and what functionality it requires. Associated with this is also the issue of its performance and when it is better than non-repeater approaches. In this talk, we explore such issues by taking incites from the conventional telecommunication world and use them to establish a framework for what quantum repeaters are and how their performance can be established. As part of this we clearly show that non-repeater approaches can exceed the direct transmission bounds. We extend these concepts to quantum networks and show one must be extremely careful when establishing the optimal communication bounds within them.

Peter P. Rohde

William J. Munro, Kae Nemoto, Nicoló Lo Piparo

Quantum communication which is our ability to transmission quantum information between remote locations is a primitive operation necessary for a future quantum internet. Quantum communication at its heart relies on establishing entangled links between remote locations which can then be used to teleport quantum data. Typically channel losses limit the distance that photons can be sent without some form of quantum repeater networks which segments the channel into smaller pieces. Entanglement distribution, purification and swapping operations then allows one to create high fidelity entangled pairs between the desired remote locations. Several generations of quantum repeaters have been proposed with dramatically increasing performance but the ultimate network performance is limited by channel losses which are typically fundamental in nature. Here we introduce the concept of quantum multiplexing, which allows us to both minimize the number of photons needed in the entanglement distribution processing but also enhance the quality of the entangled pairs generated. In this presentation we discuss the potential performance gains our quantum multiplexing approach gives.

Yu Mimura, Tomoki Takahashi, Yuhei Sekiguchi +1 more

Rodney Van Meter

The coming Quantum Internet will bring us new capabilities: advanced cryptographic functions, high-precision sensor networks for uses such as high-resolution astronomy, and secure distributed quantum computing. Experimental progress on the components for quantum repeaters is moving at a dizzying rate, and theorists have proposed various approaches to managing errors to create high-fidelity quantum entanglement. Building quantum networks presents different challenges from building quantum links. I will give an overview of these issues, then discuss the even more daunting challenge of creating a network of networks -- an internetwork -- and show how our simulations are guiding the design of a true quantum Internet. These challenges include routing (path selection), resource management such as multiplexing techniques, and security considerations within individual networks. Recently, we have discovered that it is possible for a single hijacked quantum repeater to frame other repeaters as malicious, substantially disrupting network operations. All of these issues are magnified when discussing autonomous networks that exchange information, known as an internetwork. In internetworking, not only is the scale of the problem daunting, but heterogeneous technologies will be deployed and demand interoperability at the logical level as well as the physical. Network operators also prefer to maintain the privacy of their own network operations, requiring mechanisms including connection establishment to operate with minimal sharing of information across network boundaries.