Last night, while I was sleeping, the US Department of Energy announced plans to build a Quantum Internet. This has me literally giddy with excitement. Here’s why:
- It recognises the potential for quantum communications networks to do more than simply distribute cryptographic keys. For quite some time there has been interest in establishing long-range quantum networks in order to allow quantum key distribution (QKD) to be used to securely establish cryptographic keys between nodes. To me, however, this has always seemed an uninspired use of a quantum network. As someone who wrote half his thesis on distributed architectures for quantum computing, to me the primary reason to build a quantum network has always been as a way to connect quantum computers. This is recognised in the report, which mentions three different use cases: quantum sensor networks, upscaling quantum computing (by networking smaller devices into a single larger computer) and secure quantum communications. Even this last use case mentions blind quantum computing (BQC) alongside QKD as an application, which gives me something of a personal connection to the blueprint: I’ve spent many years working on BQC, and invented the first universal BQC protocol with Anne Broadbent and Elham Kashefi back in 2008. The report cites a 2017 review I wrote on secure quantum computing protocols.
- The blueprint identifies some important areas as Priority Research Directions. Alongside the obvious building blocks of quantum repeaters and quantum error-correction, which will be needed to construct any unbroken long-range quantum communications link, the document also highlights the need for interoperable components. PRD 2 specifically calls for “Integrating existing components by unifying their operational properties (bandwidth, wavelength, duty-cycle) using systems-level engineering.” I am also delighted to see the important work of formulating routing protocols and other foundational protocols for operating a large-scale heterogeneous quantum network being recognised. Stephanie Wehner and Rod van Meter, among others, have been developing such protocols in recent years and it is great to see this kind of foundational theory work highlighted.
- It looks like they actually will try to build a nationwide network. The Department of Energy’s announcement specifically states “Eventually, we will connect all 17 DOE National Labs as the backbone of the Quantum Internet.” As I previously wrote, much of my motivation for entering the quantum computing field was a desire to relive the excitement of the early days of computing, and frankly ARPANET was a pretty big milestone. If this doesn’t sound like a quantum ARPANET, then I don’t know what does.
For those interested in quantum internet technology development, I highly recommend the WQRN conference, which I can only hope will become a more frequent event in light of this announcement.
