Seeing Atoms More Clearly

In his otherwise excellent review of x-ray holography (Physics Today, April 2001, page 21), Richard Fitzgerald writes, "Lens aberrations in electron microscopes have prevented . . . atomic resolution in electron holography." However, this is no longer true. Alexander Orchowski, Wolf-Dieter Rau, and Hannes Lichte¹ describe experimental off-axis electron holography with atomic resolution. This is the first paper that actually does what Dennis Gabor wanted to do—correct electron-optical aberrations to see atoms. Other groups have also done this since. The resolution of the best electron microscopes is now about one angstrom (better if in-line holography is used), which is sufficient to "see atoms."