In the year since physicists at the University of Colorado at Boulder and the National Institute of Standards and Technology (NIST) announced the creation of a new state of matter, scientists around the world have begun building equipment aimed at replicating the discovery.
CU-Boulder professors and physicists Eric Cornell and Carl Wieman of JILA, a joint institute of CU-Boulder and NIST, led a team of scientists that announced the creation of the long-sought Bose-Einstein condensate on July 13, 1995. They have spent the past year conducting further research on the condensate's properties and speaking to scores of scientific groups in several countries.
The Smithsonian Institution requested the carrot-sized glass container in which the first Bose-Einstein condensate was formed, but has not yet received it because it is still in use.
Predicted by Albert Einstein in 1924, the condensate occurs when individual atoms meld into a "superatom" behaving as a single entity at temperatures just billionths of a degree above absolute zero.
Scientists now believe the Bose-Einstein condensate could lead to the development of an atomic laser. Such a device would harness atoms the way a laser harnesses light and may enable the creation of extremely precise measuring devices.
The Colorado group has carried out a number of measurements looking at the properties of the condensate. These include measuring the precise temperature at which atoms freeze into the condensate, and seeing how the condensate quivers when it is gently poked. They also have built a new apparatus that produces far larger condensates.
Replicating the discovery outside of Colorado has proven to be more difficult than was predicted a year ago. Only one team led by Wolfgang Ketterle at the Massachusetts Institute of Technology has provided solid evidence of producing condensates.
"He has many more atoms in the condensate than we produced in our original apparatus, and is busy measuring many of the same things about the condensates as we are," Wieman said.
The original Colorado apparatus that produced a condensate of 2,000 rubidium atoms for 15 to 20 seconds can now make condensates of about 10,000 atoms. A new apparatus at JILA is trapping about a million atoms. The MIT group has reported trapping up to 5 million sodium atoms.
A group at Rice University claimed to have created a Bose-Einstein condensate about a month after the JILA team but some questions have lingered about the interpretation and reproducibility of their results, Wieman said.
CU-Boulder and NIST officials have decided not to seek a patent on the Bose-Einstein condensate but to donate it to the public, although several patent attorneys were of the opinion that it could be patented, said Steve ONeil, director of technology transfer and industry outreach for CU-Boulder.
About 60 theoretical papers have been written on the subject over the past year and both Cornell and Wieman have been deluged with speaking requests.
"We have received requests to talk at virtually every major U.S. university and every major conference in related subjects anywhere in the world," Wieman said. "At many of these places they are arranging special lectures and entire special sessions on this work. I long ago lost track of how many talks we have given."
About 50 scientists from several countries will meet at JILA from July 29 through July 31 for a workshop on the Bose-Einstein condensate. Other special conferences and workshops will be held around the world over the next two years.
The two physicists also received several awards. Cornell won the Stratton award from NIST, the organization's highest scientific award, and the Zeiss prize given by the Zeiss microscope company. Wieman won the Richtmyer lecture award from the American Association of Physics Teachers and was named the 88th Distinguished Research Lecturer at CU-Boulder for 1996-97. Both Wieman and Cornell will receive the prestigious Fritz London Award for low-temperature physics next month in Prague, Czech Republic.