William Daniel Phillips

William Daniel Phillips (born November 5, 1948) is an American physicist who shared the 1997 Nobel Prize in Physics for the development of methods to cool and trap atoms with laser light. Born in Wilkes-Barre, Pennsylvania, Phillips earned a B.S. from Juniata College in 1970 and a Ph.D. from the Massachusetts Institute of Technology in 1976, where his thesis involved precise atomic physics experiments. After a postdoctoral fellowship at MIT, he joined the National Bureau of Standards (now NIST) in 1978, initially working on precision electrical measurements before shifting to atomic physics. At NIST, Phillips pioneered techniques such as the Zeeman slower, which uses lasers and magnetic fields to decelerate neutral atoms, and the first magnetic trap for them, along with demonstrating sub-Doppler cooling to temperatures below theoretical limits. These innovations enabled unprecedented control over atomic motion, foundational for applications in quantum computing, atomic clocks, and Bose-Einstein condensates. As a NIST Fellow and adjunct professor at the University of Maryland, he continues research in atomic physics and quantum information.