Yale physicists have created a "squeezed state" of atoms using Bose-Einstein condensate (BEC), a sample of rubidium atoms so cold that all of the atoms collapse into a single quantum state.

The results of their study, published in a recent issue of Science, may lead to improvements in the field of precision measurement and could improve navigational systems on planes and ships.

"Our experiments are the first to observe number-squeezed states in a sample of atoms," said Chad Orzel, postdoctoral associate in physics at Yale and first author on the study. "Combining the number-squeezed states that we make with the techniques used in atom interferometry, we hope to dramatically improve the sensitivity of detectors for rotation and acceleration, and gradients in gravity. Accelerometers and gyroscopes (rotation detectors) are currently used in navigation systems for planes and ships, and gravity gradiometers have applications in submarine navigation, and in locating ore deposits for mining."

Mark Kasevich, a collaborator on the study, said creating a squeezed state of atoms is like playing a game of modified ice hockey, using a special puck and a very narrow goal. "The object of the game is to get the puck into the goal, but in this modified game, the puck diameter is initially wider than the width of the goal, making it nearly impossible to score a goal," Kasevich said. "But if the puck is made of a deformable material, it could be squeezed into a long, thin, cigar-like shape. Although the puck's length greatly exceeds its width, if the puck is shot head-on into the goal, it could now go through. At this point we don't care that the puck is elongated, so long as its width is narrower than the width of the goal, we can score."

Kasevich said many quantum-mechanical precision measurements are similar to this. "Often we can trade-off a parameter we care about in one dimension, such as the number of atoms or the width of the puck, for something we don'
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Contact: Karen N. Peart
karen.peart@yale.edu
203-432-1326
Yale University
16-Apr-2001