STEVEN CHU Biography - Famous Scientists


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Steven Chu is the Theodore and Frances Geballe Professor of Physics and Applied                 
Physics at Stanford University. Professor Chu's research is primarily in atomic                 
physics, quantum electronics, polymer and bio-physics. He became the sixth                     
director of Lawrence Berkeley National Laboratory on August 1, 2004.                           
His thesis and postdoctoral work at Berkeley, the observation of parity non-conservation       
in atomic transitions in 1978, was one of the earliest atomic physics                           
confirmations of the Weinberg-Salam-Glashow theory that unifies the weak and                   
electromagnetic forces.                                                                         
While at Bell Laboratories he and Allen Mills did the first laser spectroscopy                 
of positronium, the bound state of an electron and positron in 1982. They went                 
on to measure the 1s-2s energy level splitting of that atom to an accuracy of a                 
few parts per billion. They also made the first measurement of the corresponding               
transition in muonium, an atom consisting of muon+ and an electron. He also                     
worked on exciton energy transfer in solids and picosecond pulse propagation in                 
In 1985, he led the group that showed how to first cool and then trap atoms with               
light. The optical trap was also used to trap microscopic particles in water:                   
these so-called "optical tweezers" are widely used in biology. The first optical               
trapping was followed by the demonstration of the magneto-optic trap, the most                 
commonly used atom trap. After joining the Stanford Physics Department in 1987,                 
Chu (and independently, Dalibard and Cohen-Tannoudji) explained how multi-level                 
atoms can be cooled far below the minimum temperature predicted by the theory of               
two-level atoms. His group also demonstrated the first atomic fountain and then                 
made the first atomic fountain frequency standard to exceed the short term                     
stability of atomic clocks maintained by standards laboratories. They developed                 
a novel atom interferometer that has already exceeded the accuracy of the most                 
accurate commercial inertial sensors.                                                           
Using the optical tweezers, Chu developed methods to simultaneously visualize                   
and manipulate single bio-molecules. Using this new technique, his group have                   
used single DNA molecules to address a number of problems in polymer science.                   
His group is also applying methods such as fluorescence energy transfer, optical               
tweezers and atomic force microscope methods to study the protein and RNA                       
folding, translation and other enzyme activity at the level of individual bio-molecules.       
Chu has been awarded the Herbert Broida Prize for Spectroscopy (American                       
Physical Society, 1987), Richtmyer Memorial Prize Lecturer (APS/AAPT, 1990), co-winner         
of the King Faisal International Prize for Science (1993), the Arthur Schawlow                 
Prize for Laser Science (APS, 1994), the William Meggers Award for Laser                       
Spectroscopy (Optical Society of America, 1994), the Science for Art Prize (Louis               
Vitton - Möet Hennesey, 1995), and co-winner of the Nobel Prize in Physics (1997).             
Chu received a Humboldt Senior Scientist award (1995) and the Guggenheim                       
Fellowship (1996).                                                                             
He is a member of the National Academy of Sciences, the American Philosophical                 
Society, the American Academy of Arts and Sciences, and the Academica Sinica. He               
is also a foreign member of the Chinese Academy of Sciences and the Korean                     
Academy of Science and Engineering.