By Andrew Grant
Editor’s note: The study described in this article was retracted in the Jan. 9, 2015 Science. IBM physicist Daniel Rugar says that when he and his team attempted to replicate the experiment, they realized that the signal for a particular atom in the diamond, carbon-13, could be mistaken for that of a proton. Based on this finding, the authors of the study concluded that they did not have sufficient evidence to claim the detection of a single proton.
A small MRI-like device made of diamond has performed a scan of a single proton, an achievement that’s a big step toward using magnetic imaging to look in-depth at viruses, proteins and other nanosized biological objects.