Two University of Rochester scientists have excited a single electron within an atom so that it is in two places at once, an article published in the August 14, 1995 issue of Physical Review Letters reveals.
The article describes how Professor Carlos Stroud and his student Michael Noel in the Institute of Optics used a pair of ultrashort laser pulses to energize one electron in a potassium atom into a strange state in which it is not in one single location, but simultaneously at two points on the opposite sides of an elliptical orbit about the nucleus. The orbit, like that of a satellite around the earth, is enormous by atomic standards, some 50,000 times the size of a normal atom.
In these experiments the electron demonstrates another facet of its quantum mechanical "dual personality." It can be not only at two places simultaneously, but it also can behave like two waves and actually interfere with itself. By careful adjustment of the phases of the two laser pulses, the optics team was able to manipulate this interference to control the electron within the atom in a precise fashion, making it vanish on one side of the orbit and appear far away on the other.
"It has become common in a number of laboratories around the world to image and even move around individual atoms," said Stroud. "The next step for us was to get inside of the atom and begin to manipulate the electrons." He goes on to say that "the primary motivation of these experiments is to learn more about basic physics, but since the electrical, mechanical, chemical, and optical properties of atoms are determined by spatial distributions of their electrons one can foresee applications in a number of fields."
This pathbreaking work of Stroud and Noel has gained the attention of a number of major news organizations, and has recently been reported on in the New York Times, Science, Science News, Scientific American, Physics Today, and Physics World.