Sep 13 2007
Scientists at the University of California-Riverside physics lab have created under laboratory conditions a most unusual form of matter: Positronium in molecular form, which is composed of discrete molecules of electron-positron (anti-electron) pairs.
Now, why they're calling these molecules I have to wonder - technically they'd be an exotic and rare form of atom and not molecule (because molecules are made up of multiple atoms). Maybe the reporter got his or her facts wrong. Still, this is definitely a breakthrough in particle physics because it represents a stable (for a couple of seconds, at least) axis of matter and antimatter in the lab. Speculation toward use of such an unusual form of matter in self-sustaining fusion reactions is rampant.