Joshua Vogelstein points me to this blog entry by Robert Tucci, diplomatically titled “Unethical or Really Dumb (or both) Scientists from University of Adelaide ‘Rediscover’ My Version of Grover’s Algorithm”:
The Chappell et al. paper has 24 references but does not refer to my paper, even though their paper and mine are eerily similar. Compare them yourself. With the excellent Google and ArXiv search engines, I [Tucci] would say there is zero probability that none of its five authors knew about my paper before they wrote theirs.
Chappell responds in the comments:
Your paper is timestamped 2010; however the results of our paper was initially presented at the Cairns CQIQC conference in July 2008. . . . The intention of our paper is not a research article. It is a tutorial paper. . . . We had not seen your paper before. Our paper is based on the standard Grover search, not a fixed point search. Hence, your paper did not come to our attention, as we were not concerned with that specific topic and indeed the fixed point search is not mentioned at all in our paper.
Tucci doesn’t buy it. I don’t know what to think, neither do I really care, as I know none of the people involved and I know nothing about the topic. When I hear “Grover,” all I can think of is Sesame Street. But the form of the dispute is interesting. I imagine that people closer to this field of research will be able to tell right away what really happened here.