Thirty years of Bose-Einstein Condensates

The first Bose-Einstein Condensate (BEC) was first created by Eric Cornell, Carl Wieman, Mike Anderson, Jason Ensher, and Michael Matthews on June 5, 1995 in JILA at the University of Colorado Boulder. This new state of matter was first predicted 70 years earlier. Satyendra Nath Bose first described the quantum statistics of what we now call bosons, and Albert Einstein extended the theory to show that non-interacting bosons could condense into a single macroscopic quantum state at low temperature. 

The group used a magneto-optical trap to cool and trap about 100,000 atoms of 87Rb, then evaporatively cooled the gas to 170 nanokelvin at which point most of the atoms condensed into the harmonic oscillator ground state of the trap. They measured the temperature and condensation by releasing the atoms by shutting off the magnetic field and allowing the pinhead-sized clump to expand ballistically for a few milliseconds. A laser pulse tuned to the resonant frequency illuminated the growing blob, and the resulting shadow was captured on CCD camera, measuring the momentum distribution of the atoms (figure below left). The data converted to a 3D representation (figure below right) shows that the blue-labeled atoms are in the asymmetric harmonic oscillator ground state, with the remainder in a symmetric gaussian whose width measures the temperature. The group immediately recognized the significance of their discovery, quietly confirmed the experimental results, and wrote and submitted the paper to Science. Their paper was published on July 14, 1995, with the cover image showing the BEC. Their discovery culminated decades of research by many physicists aimed at creating a BEC. 

Cornell, Wieman, and Wolfgang Ketterle from MIT who created a BEC a few months later using sodium, shared the 2001 Nobel Prize in Physics for their discovery. Bose-Einstein Condensation has become a leading tool in atomic, molecular, and optical physics, providing extremely sensitive quantum sensing and control for use in many applications. Its extension with the development of optical lattices is the cornerstone in the development of laser-based atomic clocks.  

Where are they now? 

Eric Cornell is Professor Adjoint and a fellow of JILA and NIST. His recent research includes measuring the best limit on the electric dipole moment of the electron. Eric won the 2024 Outstanding Physics Teacher Award based primarily for teaching PHYS 1125 Electricity and Magnetism to first-year physics majors. 

Carl Wieman is Professor of Physics and Graduate School of Education at Stanford University. He specializes in undergraduate physics and science education and pioneered the use of experimental techniques to evaluate the effectiveness of various teaching strategies for physics and other sciences. He served as Associate Director for Science in President Obama’s White House Office of Science and Technology Policy, and then as Professor of Physics, and Director, Carl Wieman Science Education Initiative at the University of British Columbia. He was the founder and remains as the Senior Advisor to PhET, CU’s premier online science education interactive app developer with over 1.7 billion world-wide deliveries of over 118 apps in 128 languages.  

Mike Anderson (PhDPhys’92) was a postdoc at the time of the discovery. He was President and CEO of Vescent Photonics for 17 years, and continues as a member of their Board of Directors. Prior to that he was Vice President for Engineering at Meadowlark Optics.  

Jason Ensher (PhDPhys’99) is Senior Director of Engineering at nLIGHT, Inc. Prior to that he was Executive Vice President and Chief Technology Officer at Insight Photonic Solutions. 

Michael Matthews (PhDPhys’99) is Sensor R&D Physicist & Engineer at Insight M. Prior to that he was Staff Hardware Engineer at Waymo, Technical Director of Sensors at AOSense, Inc., and Research Specialist at 3M.

Written by Paul Beale / CU Boulder Physics Director of Alumni Relations