By Peter Weiss
From Long Beach, Calif., at a meeting of the American Physical Society
Like a race car forced to stay within certain lanes of a speedway, a lone electron in a circular path should whirl along exclusively in specific allowed orbits, the rules of quantum mechanics say.
In a Harvard University laboratory, physicists have devised an extraordinarily small, low-energy cyclotron in which a single orbiting electron vividly demonstrates that predicted quantum behavior.
Moreover, this artificial atom without a nucleus, as Gerald Gabrielse and his colleagues refer to their diminutive apparatus, promises to make possible the most precise measurements yet of certain fundamental constants. “We think we can measure the strength of the bar magnet in the electron, called its magnetic moment, 10 times better than ever before,” Gabrielse predicts.