CS Forum: Simon Devitt "Quantum networks: high-bandwidth and low-latency communication"

CS forum is a seminar series arranged at the CS department. Welcome everyone!
CS Forum

When? Thursday 9 Dec at 14:15-15:00
Where? Online in Zoom

Quantum networks: high-bandwidth and low-latency communication

Dr. Simon Devitt
University of Technology Sydney, Australia


Quantum communications networks are an important component in the quantum technology ecosystem. Currently in their infancy, quantum communication systems currently consist of point to point connections that are primary used for quantum key distribution protocols. Despite this infancy, there has been significant technological investment and progress, with several countries, most notably the Chinese, launching successful satellite systems demonstrating both Quantum Key Distribution and entanglement distribution over distances up to 1,200km. Despite these achievements, the theoretical design and experimental construction of a quantum network that would mimic the distance and speed performance of the classical internet has been elusive. Specifically, the network performance of quantum repeater or quantum satellite systems, even under optimistic engineering assumptions, would be orders of magnitude worse than the classical internet, precluding the development of a quantum internet that would augment, or perhaps in the future, replace the current classical internet. 

Our solution is a quantum variant of the sneakernet principle of network design. A downside of classical sneakernets is the issue of information latency. If the shipping route, for example, takes days, in not weeks, to transfer information from source to receiver then there is a significant latency between when the information is loaded onto a memory unit and when it is read out at the receiving end.

In contrast, a quantum sneakernet does not suffer from significant latency on information transfer. Unlike a classical sneakernet, a quantum sneakernet does not transfer actual information. Instead, a quantum sneakernet distributes a quantum resource that can later be used for information teleportation protocols. Hence, this resource state is distributed slowly, offline, before any information is transmitted. We essentially prepare a virtual quantum “information pipeline” using sneakernet principles which can then be consumed at a later time to transmit quantum information. In this work we describe large-scale quantum network architectures that are based on quantum sneakernet principles. We outline the basic information transfer protocols, what are the requirements of the quantum technology to realise this type of network and how a quantum sneakernet can be used to form a high-bandwidth, low error rate truck system to a quantum internet.

Speaker bio

Simon Devitt is a Senior Lecturer in the centre for quantum software and information at the university of technology Sydney and co-founder and managing director of the quantum technology consultancy firm, h-bar.  His expertise is in quantum computing and communications architecture design, quantum error correction and quantum algorithm compilation.  Along with over 100 academic publications, he has worked with numerous corporations and VC firms on their expansion into the quantum technology space and advised multiple government agencies on multimillion dollar R&D initiatives.  In 2020, he was awarded the inaugural Warren Prize from the Royal Society of NSW for his service to global quantum technology development.


Assistant Professor Alexandru Paler, Department of Computer Science

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