From 2006 through 2010, I participated on a large, $1.5-million-a-year Quantum Computing Concept Maturation (QCCM) in optical quantum computing that was funded by the Intelligence Advanced Research Projects Activity (IARPA), which was formerly known as the Disruptive Technology Office, which was formerly known as the Advanced Research and Development Activity (ARDA), which was formerly known as the NSA, which were all funding agencies for the US intelligence community. The changes in names, acronyms, and, more importantly, the logos took place at a frightening pace that made it hard for the research scientists to keep up. I personally had funding for optical quantum computing from 2000 to 2010, which came under the umbrella of each of these agencies in sequence and there were even two separate logos for IARPA in use at the same time. When the acronym IARPA showed up in 2007, all my colleagues would ask me, what the heck is IARPA? To this I would respond, it is the Defense Advanced Research Projects Agency (DARPA) for spies (see Figure 4.9).
But in any case, the photonic QCCM, led by American physicist Paul Kwiat, had collaborators that stretched from Austria (Anton Zeilinger) to Australia (physicist Andrew White). We had what we all thought were great results; we submitted in 2010 an essentially renewal proposal and we were not funded and neither was anybody else in photonic quantum computing.
In the case of photonic qubits, this dropping of optical quantum computing by IARPA was a bit hasty in my opinion. While the photonic quantum computer may be a bit of a long shot for the scalable quantum computer, all hardware platforms are a long shot, and photonics is the only technology that would allow us to build the scalable quantum Internet. There is a good analogy. In the 1970s and 1980s, there were predictions that silicon chip technology was coming to an end, and there was a great DoD-funded push to develop scalable classical optical computers. The thought was that as we put more and more circuits closer and closer together on the silicon chips, the electromagnetic cross talk between the wires and the transistors would grow without bound limiting the number of processors on a chip. What was not foreseen was the development of good integrated circuit design rules, developed by American computer scientists Caver Mead, Lynn Conway, and others, which showed that the cross talk could be completely eliminated. But until that was understood, the funding for the competing optical computing rose and ran for a while and then collapsed in the mid-1980s when it became clear that the Intel silicon chips were not going anywhere and that predictions of their demise were overrated. The optical classical computer program was viewed as a colossal failure and to say you were working on optical classical computing became the kiss of death. But it was not a failure at all. The optical switches and transistors developed for the scalable optical classical computer found their way into the switches and routers and hubs for the fiber-optic-based classical Internet. The future quantum Internet will also require the manipulations of photons at the quantum level—a quantum repeater is a device for transmitting quantum information over long distances. The quantum repeater is a small, special-purpose, optical, quantum computer that executes a particular error correction protocol. The future of the quantum Internet is in photons and the short circuiting of the development of optical quantum information processors in the United States means that the future quantum Internet will have “Made in China” stamped all over it.
Figure 4.9: A composite study of the logos of ARDA throughout the ages. From 2000 to 2010, I had continuous funding for research in quantum information processing, which as far as I could tell came from one place, but for which I had to change logos five times, starting with the NSA logo on the left (2000) and ending with the second IARPA logo on the right (2010). The penultimate IARPA logo on the right had a life span of only 2 weeks and you can see that it is the logo for the Director of Central Intelligence with the letters IARPA badly and hastily photoshopped across it. In the background is a spoof of a composite map of the lands of Arda from the fictional works of J.R.R. Tolkien. (The sea monster and sailing ship are taken from ancient manuscripts and no longer subject to copyright. The map is based on “A Map of Middle Earth and the Undying Lands: A Composite Study of the Lands of ARDA,” author unknown. (Explanation of the jokes: The Unlying Lands should be the Undying Lands in Tolkien’s works. Nimanrø should be Numenor, Mittledöd should be Middle Earth, Odinaiä is Ekkaia, and Darpagar is Belegaer. ODNI is the Office of the Director of National Intelligence, NIMA is the National Imaging and Mapping Agency [now the National Geospatial-Intelligence Agency], NRO is the National Reconnaissance Office, DARPA is the Defense Advanced Research Projects Agency [parts of which were carved out into ARDA], and DoD is the Department of Defense.)
This post is directly quoted from my book, Jonathan P. Dowling, Schrödinger's Killer App — Race to Build the World's First Quantum Computer (Taylor & Francis, 2013) pp. 171–173.