Professor David E. Pritchard

Biography

MIT

dpritch@MIT.EDU

 Born in New York City in 1941, David E. Pritchard graduated from Caltech (B.Sc.  1962) and Harvard (Ph.D. 1968).  Employed since then in the physics department at MIT where he is currently Cecil and Ida Green professor, he has pursued research in atomic, optical, and molecular physics. 

Pritchard was a pioneer in the study of the mechanical forces of light on atoms that lead to the Nobel Prize in physics in 1997 being awarded to Bill Phillips (his former postdoc), Steve Chu (a collaborator), and Claude Cohen-Tannoudji.  His group invented the widely used magneto-optical laser trap for neutral atoms and a high density variant called the dark spot MOT.  These traps are the workhorses in the field of cold atom research and, together with a magnetic atom trap Pritchard invented, have recently been used by many groups to attain Bose-Einstein condensation. The 2001 Nobel Prize in physics was awarded to Pritchard’s former postdoc Wolfgang Ketterle who took over Pritchard’s cold atom research program when he became as assistant professor at MIT; he shared it with Pritchard’s former graduate student, Eric Cornell and Carl Wieman who was a Pritchard mentee as an undergraduate at MIT.

Pritchard’s group also pioneered the field of atom optics, in which quantum mechanical atom waves are manipulated like light waves in conventional optics.  They demonstrated diffraction gratings for atoms made from both standing waves of light and nanofabricated membranes.  The group used these gratings to make the first true atom interferometer, which has been used to measure inertial motions with sensitivity comparable to laser gyroscopes and to measure atomic and molecular properties.  Their atom interferometer can address fundamental issues in quantum mechanics as demonstrated by their performing a thought experiment (gedankenexperiment) proposed by Feynman which probes the quantum decoherence due to scattering a single photon from an atom wave passing through the interferometer.   Recently his group has demonstrated phase coherent atom amplification in a collaboration with Ketterle’s that is developing atom optics techniques using Bose Einstein Condensates.

Pritchard’s group has constructed the world's most accurate mass spectrometer by measuring single trapped ions.  Among other applications, it was used to recalibrate the gamma ray energy scale by weighing a gamma ray and using E=mc22as well as to provide a new route to the most precise determination of the fine structure constant, alpha 

Pritchard’s group has made pioneering research determinations of potentials of the van der Waals molecules NaNe and KAr, which violate the rules you learned in high school chemistry that rare gases like Ne and Ar are chemically inert and do not form molecules.  The interaction potentials were determined both by scattering of ground state and laser-excited alkali atoms from the rare gas targets, and also by spectroscopy (laser and rf) on these molecules which were made by expanding high pressure gas into a vacuum.  Pritchard was a pioneer in the application of tunable lasers to physics and chemistry, being the first to demonstrate high resolution spectroscopy in which the system being studied absorbed two laser photons simultaneously.  His group also made measurements of atom-molecule collisions using the Doppler shift to select velocity and analyze scattering angles, and applied lasers to study atomic line broadening.

Pritchard has a life-long interest in teaching problem solving in physics.  In the 1970’s he authored a Mechanics Workbook, a programmed instruction manual for Newtonian mechanics..  He also has a large collections of puzzles and paradoxes in physics and has taught a 10-hour course in this many times during MIT’s January Independent Activities Period.  He also collects “physics for lunch” problems, each one of which typically puzzles beginning graduate students for a lunch period.  His interest in teaching people to solve problems led to the collaboration with his son, Alex on CyberTutor, an interactive web-based program which is dramatically superior to written homework in raising students’ test scores.  It is marketed as Mastering Physics by Addison Wesley (www.masteringphysics.com).  He is the undergraduate major coordinator for physics undergraduates, and has won the MIT Dean’s award for teaching and advising.

Pritchard is a member of the National Academy of Sciences, and a Fellow of the American Academy of Arts and Sciences, the American Association for the Advancement of Science, the American Physical Society, and the Optical Society of America.  He was a member of the board of directors of the Optical Society of America (1996-2000), and has been selected as Centannial Lecturer by the APS and as Distinguished Traveling Lecturer by its Laser Science Topical group, twice as Distinguished Visitor at the Joint Institute for Laboratory Astrophysics at the University of Colorado, and was awarded the 2003 Schawlow Prize in Laser Science and the 1991 Broida Prize of the American Physical Society, the latter with the citation ``For outstanding contributions to atomic, molecular and optical physics including his monumental studies of energy transfer in molecular collisions; seminal research on atom wave interferometry and atom optics; numerous studies of the forces of light on atoms and their applications to atom cooling and trapping; and his development of single ion mass spectroscopy.''  He has spent sabbaticals at SRI International and the Universite de Paris Sud at Orsay.  He has published over two hundred papers in refereed scientific journals, has two patents, and has received well over 100 invitations to speak at national or international meetings.

Pritchard's professional activities have included Director, Interbuild Corporation (1968-1973), Director, Optical Society of America (1996-2000); Head, M.I.T. Physics-Industry Forum (1981-1984), (Organized 2 day Symposia in Optics for this in 1982 and 1989); Divisional Associate Editor, Phys. Rev. Lett. (1983- 1987); N.A.S. Committee on Atomic, Molecular, and Optical Science (1989-1992); and N.I.S.T. Visiting Committee for J.I.L.A. (1989-1993, chair 1994-1995).  He has served as American Physical Society representative to Joint Council on Quantum Electronics (1986-1992) and International Council on Quantum Electronics (1989-1992); APS Laser Science Topical Group Steering Committee (1988-1991); and within the Division of Atomic, Molecular, and Optical Physics has served on the Program Committee (1974-1977), (1981-1982), (1983-1985) (1989-1993), Publication Committee (1980-1983,1987, chairman 1988) Executive Committee (1988-1991), and Broida Prize Committee (Vice Chairman, Chairman 1983-1987, 1992). He has contributed to the organization of a number of scientific meetings including General Organizing Committee, International Conference on Collisions of Electron and Atomic Physics (1977-1981); Local Organizing Committee, International Conference on Atomic Physics (1980); Organizer (with H. Rabitz), Symposium on "Quantum Number Dependence of Cross Sections" @ Las Vegas, A.C.S. Meeting 3/30/82- 4/2/82; instigator and organizer of Workshop on Controlling Atoms, D.E.A.P. Meeting 5/28/84-5/29/84, Storrs, CT.; Co-Chairman of Program Committee (with C. Shank), International Quantum Electronics Conference '87; Co-Chairman (with Arto Nurmikko), First Quantum Electronics and Laser Sciences Conference '89, and program committees including a Nobel Symposium (1994), Gordon Conference (1991 & 93), Int’l Workshops on Atom Optics (1992-..) Int'l Conf. on Laser Physics (1995), Snowbird (1997).  Most recently he was the Chair of the International Conference on Atomic Physics (MIT 2002) and a founding lecturer at the associated Summer School.