I.B.M. scientists have modified a scanning-tunneling microscope, making it possible to observe dynamic processes inside individual atoms on a time scale one million times faster than has previously been possible.
The researchers have perfected a measurement technique in which they use an extremely short voltage pulse to excite an individual atom and then follow with a lower voltage to read the atom’s magnetic state, or spin, shortly afterward.
The resulting data produces the equivalent of a high-resolution, high-speed movie of the atom’s behavior.
The advance, reported Thursday in the journal Science, has potential applications in fields including solar energy technology, computer data storage and quantum computing.
The scanning-tunneling microscope was invented by I.B.M. researchers in 1981 in Switzerland. The systems are now in wide use, and make it possible to make images of individual atoms. While they have attained astounding spatial resolutions, however, they have been less precise in detailing physical processes that occur so quickly that their duration is measured in nanoseconds. A nanosecond — a billionth of a second — is to a second as one second is to 30 years, roughly.
“This technique is really nice because it allows us to measure how things change in time,” said Michael Crommie, a physicist at the University of California, Berkeley. “Obviously people have been doing this with other techniques for many years, but it has proven hard to do at very small time scales.”