Back in 1995, I had the pleasure of visiting the IBM Almaden lab of Donald Eigler, who was announced today as a winner of this year's Kavli Prize for his work on nanoscience. Eigler made his mark nearly two decades ago when he showed how he could move individual atoms around with a scanning tunneling microscope, first to spell out the letters of his employer and later to draw images such as this stick figure made from carbon monoxide molecules. Such atomic-scale control not only can elucidate fundamental physics, but it could also be the basis for new computing and sensing technologies.
This story about my lab visit was originally published in the July 1995 issue of Scientific American.
Congratulations to Don and the other 2010 Kavli Prize winners.
In the Atomic Corral
IBM may bring to mind drab blue suits and corporate mores, but that impression is hardly the fault of its scientists. Take Donald M. Eigler of the giant’s Almaden Research Center in San Jose, Calif. Dressed in a white shirt, baggy gray pants, tennis sneakers and a purple- splashed necktie that matches his watchband, Eigler hardly exudes conservative culture. Maybe that is the privilege of being a scientist—or of living in California. In any event, it seems appropriate for someone who spends his days and nights shoving atoms around one by one using a scanning tunneling microscope.
I met him in March on a journalists’ tour of the facilities. After explaining his research, Eigler promises to let us move individual atoms if there is time after stopping by a colleague’s lab next door. It’s not long after that visit before we charge back into Eigler’s lab. I’m not sure why everyone wants to push an atom around. After all, we all can move untold billions of them every second.
Imaged on the computer screen is a blob of atoms—“ ‘BL’ on the periodic table,” Eigler cracks. The microscope, which sees by detecting electrons that tunnel between the tip of the microscope and the atom, is housed in another room. Eigler has hooked up his microscope to a stereo system, which translates the tunneling current of electrons into a staticlike hum. I poise the cursor over a BL atom before clicking on the mouse, which lowers the tip onto the blob that rests on a smooth substrate. Pop! An atom has clung to the tip. Then I drag the cursor across the screen. Clunk! The atom has just plopped into the next unit cell of the molecules that make up the substrate. Clunk! Another unit cell over. An updated image sweeps across the monitor: the blob has moved a tad to the left.
Eigler, of course, is far more adept at controlling atoms. Over the years, he and his colleagues have used them to spell out the company’s logo and to draw stick figures with carbon monoxide molecules. He has trapped electrons in atomic corrals, rendering visible the wave nature of the electron. Graphics of his manipulations have graced the pages of several publications. Eigler’s techniques promise much more than an entertaining sound-and-video show. The scanning tunneling microscope could store data as atom-size bits or forge molecules to custom specifications. The process would also prove useful, as Eigler presents it, for “spin excitation spectroscopy.” He may not wear IBM blue, but he certainly does not let you forget he’s a physicist.