Physics @ Berkeley
Physics in the News
Title: Physicists Create Cold Storage Ring
Date: 09/28/2005
Publication: The Daily Californian
Editor: Stephanie Pace
Extended Text:

 A team of UC Berkeley physicists accidentally stumbled upon the idea of a cold storage ring while running routine experiments on a device designed to study quantum electrodynamics and possible applications in quantum computers. By creating supercold atoms in a mirror cavity, the team hoped to study the interactions between light and Bose-Einstein condensates.

 Bose-Einstein condensates are neutral gas atoms cooled to a low enough temperature so that they all fall into the same quantum state. Quantum mechanics is the theory that energy does not have a continuous range of values, but is, instead, absorbed or radiated discontinuously, in multiples of definite, indivisible units called quanta.

 The research shows that billions of atoms can end up in the same place at the same time. This idea was originally proposed 80 years ago by Albert Einstein and inspired by the previous work of Satyendra Nath Bose.

 Dan Stamper-Kurn, a UC Berkeley professor of physics, led this new quantum physics study. He and colleague Subhadeep Gupta, a post-doctoral fellow at UC Berkeley, worked with physics graduate students Kater Murch, Kevin Moore, and Tom Purdy to create a Bose-Einstein condensate of rubidium atoms.

 The scientists forced the condensate into a circular racetrack two millimeters across to create a particle storage ring similar to the accelerator storage rings of high-energy physics.

 This new insight will assist in the development of sensitive gyroscopes for use in research or navigation systems for satellites or aircraft. A gyroscope is a spinning mass mounted on a base such that its axis can turn freely while maintaining its orientation.

 "In addition to its application as sensitive rotation sensors, it can also lead to possible formation of new types of quantum systems, in particular highly stable, persistent angular momentum states," Gupta said. "Circular geometry makes more sense to detect rotation."

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