PHYSICS DEPARTMENT

Students and faculty in the Physics Department won a number of important national awards during the 1999-2000 academic year. For his senior honors thesis Brian Gerke ’99 won the American Physical Society (APS) Apker Award. Only two Apkers are awarded each year to recognize “exceptional achievements in physics research by undergraduate students.” The APS also elected Professor Bill Wootters to the status of Fellow for his “contributions on the foundations of quantum mechanics and groundbreaking work in quantum information and communications theory.” Each year the APS elects no more than one half a percent of its membership to Fellow status. The National Institute for Standards and Technology (NIST) awarded a 1999-2001 Precision Measurement Grant to Assistant Professor Tiku Majumder. This highly competitive $150,000 grant will help finance Majumder’s search for T-violating forces in atomic thallium.

Summer research: Professor Daniel Aalberts and Rachel Horwitz ’03 analyzing the structure of folded proteins.

These accolades demonstrate that student-faculty research is an essential part of our academic program. Grants from the National Science Foundation (NSF), NIST, and Research Corporation, as well as generous donations from alumni, allow us to hire several students to work with us full time on our research in the summer. During summer 1999, nine Williams students and two students from other colleges joined our faculty to work on experimental and theoretical projects. Five of those students continued their research during the academic year, completing honors theses. This coming summer (2000) we will have twelve students from Williams working with us. The students meet regularly for tea and cookies, as well as for more formal talks given by faculty or students. Those students doing experimental projects take a short course on machine shop work and another on electronics.

As part of the science facility construction project, the College renovated 2,800 square feet of space in the basement of the Bronfman Science Center for use as a laser facility. During January and the beginning of the summer, professors Jeff Strait, Sarah Bolton, and Tiku Majumder moved their laboratory equipment into the new space. Professor Kevin Jones will join them when he returns from sabbatical in the fall. The new laser facility consists of six contiguous laboratory rooms with all of the utilities and fixtures necessary for modern optical experiments. We anticipate that this new facility will enhance our very active student and faculty research collaboration.

Also part of the science facility project, extensive renovation work began in January on the Thompson Physical Laboratory. The original part of TPL was built in 1891. At that time, it was considered so remarkable that the first volume of Physical Review included a lengthy description of the building. In January, we moved out of TPL - completely emptying it for the first time in its history. This move was an enormous undertaking, including sorting through over a century of accumulated scientific apparatus. During the Spring Term, the astronomy offices and some of the physics offices temporarily moved to Siskind House, a wood-frame house behind TPL. Physics classes and instructional laboratories took place in Bronfman and other buildings. In the fall of 2000, we hope to move back into TPL. We look forward a new introductory physics teaching laboratory located in the former TPL Physics and Astronomy Library. Physics and astronomy alumni generously donated funds for the new teaching lab, naming it after Emeritus Professor David Park. We also look forward to a new heating and ventilation system, new chairs in the lecture rooms, and numerous other improvements to the building.

Assistant Professor Daniel Aalberts taught electromagnetism at all levels (PHYS 132, 201 and 405T) this year. He introduced numerical methods of calculation to the majors and explored the wonders of particle physics with non-majors.

Aalberts studied ultrafast dynamics of photoactive molecules with Brian Gerke ’99, Ben Cooper ’00, and Fritz Stabenau ’02. Gerke’s honors work was recognized as one of the two best American undergraduate physics theses with the American Physical Society’s Apker Award. With research student Ian Eisenman ’99, he also studied a variant of a classic problem in mechanics, finding the fastest path between two points in a gravitational field. This summer he is looking forward to continuing his work with Stabenau on retinal and to initiating research in protein folding with Rachel Horwitz ’03 and in lipid bilayers with John Parman ’02.

Aalberts was awarded a $37,500 Cottrell College Science Award to study “Quantum Coherent Dynamics of Photoactive Molecules.” He did an on campus presentation entitled “Phase Transitions and (Hard-Spin) Mean Field Theory” for the Summer Research Program. Aalberts sang lead with a quartet of Williams scientists, The Diminished Faculty, advised the Williams chapter of the Society of Physics Students program, and was inducted into the Cedar Rapids Jefferson High School Hall of Fame.

Assistant Professor Sarah Bolton taught PHYS 301, Introduction to Quantum Mechanics in the fall. In the spring she taught PHYS 109 Sound, Light and Perception, as well as a new course, Materials Science: The Chemistry and Physics of Materials (PHYS/CHEM 318). The new course in materials science was developed and team-taught with Professor Lee Park of the Chemistry Department. The course forms the core of a new interdisciplinary cluster in Materials Science, and attracted students from the Biology, Chemistry and Physics departments.

Bolton worked with Mark Acton ’00 in studies of an ultrafast Titanium Sapphire laser. The laser produces pulses of less than 20 femtoseconds in duration (20 x 10^-15 seconds) – short enough to take “snapshots” of electron motions and molecular vibrations. This laser is being used to study dynamics of ultrafast optical systems, including nonlinear dynamics and chaos. Mark made great progress on this system in the past year, using novel measurement and data analysis techniques to obtain the first conclusive demonstration of chaos in a femtosecond laser. Work on this project will continue in the summer of 2000 with students Camille Burnett, ’01, Daniel Bissex, ’02, and Sarah Reynolds, ’02. The work is supported by grants from the NSF and Research Corporation.

Professor Stuart Crampton was on leave all year. He spent the fall in Berkeley, CA as a Visiting Scholar at the Center for Theology and the Natural Sciences. In the spring, he continued his research into the implications for religion of modern science at General Theological Seminary with Professor Mark Richardson and at Williams with Professor Will Dudley. He continues to serve on the Board of Directors of Research Corporation and as a consultant to the Sherman Fairchild Foundation Scientific Equipment Program.

Professor Kevin Jones was on sabbatical at the National Institute of Standards and Technology in Gaithersburg, MD. He has a long-standing research collaboration with a group there headed by William Phillips. When Phillips was awarded the 1997 Nobel Prize in Physics, he invited Jones to come to Gaithersburg for an extended two-year sabbatical. This research group has developed techniques for slowing atoms to near absolute zero. Jones, working with Paul Lett and others, has been “photoassociating” these cold (< 0.001 degrees Kelvin) sodium atoms to produce Na₂ molecules. For her senior honors thesis Ginel Hill ’00 worked with Jones to develop a technique for experimentally labeling the hyperfine structure in a particular molecular state. In addition to this molecular spectroscopy, Jones has shown how light can be used to alter the nature of collisions between these very cold atoms. In February Jones was an outside examiner for a Ph.D. defense at the University of Utrecht in Holland.

During the 1999-00 year, Assistant Professor Protik “Tiku” Majumder taught PHYS 141, Particles and Waves – Enriched; Labs for PHYS 142, Physics Today; and PHYS 400, Thermal and Statistical Physics. In July 1999, Majumder was awarded a Precision Measurement Grant from the National Institute of Standards and Technology (one of two awarded nationally each year). This three-year $150,000 award will support equipment and personnel to pursue a new experimental test of fundamental Time Reversal symmetry in atoms. During the summer of 1999, Majumder supervised two students in the summer research program. Andrew Speck ’00 began work on his senior thesis project, and was aided over the summer by NSF/REU student Paul Grinberg (Hiram College ’00). Both worked closely with current postdoctoral associate, Dr. David Richardson on our laser spectroscopy experiments. Data was collected and analyzed to complete the experimental work begun by previous thesis student Rob Lyman ’99. A summary of this work will appear in the journal Physical Review A in July 2000. During the academic year, Professor Majumder jointly organized a very active departmental colloquium series with Professor Bolton.

The Majumder group continues to pursue high-precision diode laser spectroscopy of thallium in their atomic physics lab. A better understanding of the structure of this complex atom is essential to be able to interpret recent precise measurements of parity nonconservation in thallium in terms of fundamental physics. Andrew Speck ’00 completed a thesis this year entitled “Measuring the Stark Shift in the Thallium 378 nm 6P_1/2-7S_1/2 Transition”. He developed and tested a scheme to measure the Stark shift by simultaneous application of a known electric field and tunable frequency shift using an acousto-optic modulator. He successfully developed the optics, electronics, interfacing, and software to digitally lock the frequency of our diode laser. Postdoc David Richardson worked with Andrew on various aspects of this project, and also began exploratory work on the NIST-funded time-reversal violation experiment. Here, an optical three mirror high-finesse ring cavity is being designed for use with an infrared 1283 nm diode laser which will eventually be incorporated into the atomic beam apparatus. Charlie Doret ’02 spent Winter Term 2000 working on various lab projects in the group, and is continuing this work during the summer of 2000. Charlie joins Andrew, new thesis student Paul Friedberg ’01 and Dr. Richardson this summer. During the month of June 2000, the group moved the Majumder lab into the new Laser Facility in the Bronfman basement, and then traveled to Storrs, CT for the 2000 meeting of the Division of Atomic Molecular and Optical Physics (DAMOP) of the American Physical Society. A poster describing ongoing Majumder group work was presented and well received at the conference.

Emeritus Professor David Park, encouraged by the success of The Fire within the Eye, has begun to think about a new book, to be known as The Grand Contraption. What it will be about is anybody’s guess.

Associate Professor Jefferson Strait taught PHYS 100, The Physics of Everyday Life, PHYS 202, Waves and Optics, and PHYS 451, Solid State Physics. He also served as chair of the department this year. In addition to the routine duties of a chair, he spent a great deal of time overseeing the Physics Department’s move out of the Thompson Physical Laboratory and monitoring the subsequent renovations of that building. He also served as the pre-engineering advisor for the College and as a member of the Executive Board of the New England Section of the American Physical Society.

Strait and his students have built an optical fiber laser designed to produce pulses of light about 10^-12 seconds long. Unlike most lasers, which use mirrors to confine light to the laser cavity, an optical fiber laser uses a loop of fiber as its cavity. A section of fiber doped with erbium serves as the gain medium. Strait and his students pump the gain medium with 1.06 μm light and it lases at 1.55 μm, conveniently the same wavelength at which optical fiber is most transparent and therefore most suitable for telecommunications. During the summer of 1999, Clay Stein ’00 and Adam Halverson (Reed College ’00) continued that work. The eventual goal is to study how these short pulses propagate in optical fiber.

Professor William Wootters spent the month of July 1999 at the Isaac Newton Institute in Cambridge, England, where he participated in a program on quantum information theory, his primary area of research. At Cambridge he met with other researchers in the field and attended an intensive weeklong workshop. One of the mathematical problems inspired by the Cambridge meeting—the problem of characterizing “entangled chains” of quantum objects—led to a thesis project undertaken by Kevin O’Connor ’00. Another thesis student, Anthony Ndirango ’00, focused on the role of phase space in quantum mechanics. Both Kevin and Anthony graduated with honors and were elected to Associate Membership in Sigma Xi. In addition to the Cambridge workshop, Professor Wootters attended an American Physical Society meeting (New England Section) and two meetings of the American Mathematical Society (a national meeting and a Northeast Section meeting). Kevin O’Connor also attended the last of these conferences and was co-author of a paper presented there. Professor Wootters was elected this year to the status of Fellow in the American Physical Society.

Together with Professor Susan Loepp of the Mathematics Department, Professor Wootters was awarded an NSF grant to develop a new team-taught course in coding and cryptography. The course, which extends an earlier winter-study course, will include sections on quantum cryptography and quantum computation and will be offered jointly by the Physics and Mathematics Departments.

Staff Physicist and Coordinator of Science Facilities, Bryce Babcock, collaborated with Professor Jay Pasachoff on observations of the total solar eclipse in Rimnicu Vilcea, Romania in August 1999. He is co-author on a paper with Pasachoff, Kevin Russell ’00 and Tim McConnochie ’98 analyzing earlier eclipse data from the 1994 and 1998 eclipses that is in press in the journal Solar Physics. Preparations are in progress for experiments at the June 2000 eclipse in Zambia. (For further details regarding these experiments and other publications see the Astronomy departmental and faculty publications sections.) In addition to his work developing research and instructional laboratory apparatus for the sciences, he taught the reading course, Advanced Electronics, PHYS 456, in the spring semester. He continued to maintain the Sciences Web Site at http://www.williams.edu/BSC. This site provides information about the sciences at Williams including html versions of recent copies of the Report of Science at Williams, a calendar of science activities and information on the Science Building Project.

Mark Acton	Kevin Russell
Rebecca Cover	Matthew Scherer
Ginel Hill	Brad Slingerland
Sarah Kate	Andrew Speck
Anthony Ndirango	Clayton Stein
Kevin O’Connor	Qiang Sun

[Colloquia are held jointly with Astronomy. See Astronomy section for additional listings.]

Professor Kelvin Chu

University of Vermont

“A Physicist’s Approach to Biology: Structure, Function and Dynamics in Proteins”
Class of 1960’s Scholars Program

Professor James Heyman ’85

Macalester College

“Infrared Spectra in a Trillionth of a Second”
Class of 1960’s Scholars Program

Dr. John Sunderland ’81

Biomedical Research Foundation – Positron Emission Tomography Imaging Center

“The Physics of Positron Emission Tomography: Medical Imaging with Anti-Matter”

Professor Daniel Reich

John Hopkins University

“Low-dimensional Quantum Magnets”
Class of 1960’s Scholars Program

Adrienne Wootters

University of Massachusetts at Amherst

“Avalanches of Superfluid Helium in Porous Materials”

Froney Crawford ’94

Massachusetts Institute of Technology

“Recent Results from the Parkes Multibeam Pulsar Survey”
Class of 1960’s Scholars Program

Dr. Shawn Burdick ’81

Mt. Greylock Regional High School

“Space-Based Infrared Observations using COBE & MSX”

Professor Edward Kearns

Boston University

“The Mystery of Missing Neutrinos”
Class of 1960’s Scholars Program

Professor Eric Hessels

York University, Toronto, Canada

“Precise Spectroscopy of Atoms”
Class of 1960’s Scholars Program

Dr. Travis Mitchell

N.I.S.T. – Boulder, CO

“Plasma Crystal Experiments at N.I.S.T.”

Dr. Steven Dodge

Berkeley National Laboratory - Berkeley, CA

“Solid State Dynamics in Real Time”

Dr. Robert Leheny

Massachusetts Institute of Technology

“Quantum Magnetism in Two Dimensions”

Dr. Gustavo Stolovitzky

IBM Computational Biology Center – TJ Watson Research Center

“Analysis of Gene Expression Microarrays for Phenotype Classification”
Class of 1960’s Scholars Program

Jason Zimba ’91

University of California, Berkeley

“Bohr or Borges? Quantum Realism and the Uncertainty Relations”
Class of 1960’s Scholars Program

Dr. Christopher Shera

Harvard Medical School – Massachusetts Eye & Ear Infirmary

“Listening to the Ear”

Dr. Jonathan Friedman

State University of New York at Stony Brook

“Macroscopic Quantum Phenomena in Molecular Magnets and Squids”

Dr. David Hall

Amherst College

“Putting the Spin in a Bose-Einstein Condensate”

Professor Janice Hudgings

Mt. Holyoke College

“Mixing Light and Semiconductors: A Bright Idea”

Professor Ben Widom

Cornell University

“Hydrophobic Attraction in One, Two, and Three Dimensions”

Professor Geoffrey Nunes ’83

Dartmouth College

“Berry’s Phase and Millikelvin Force Microscopy”

Professor Paul Weber

Grinnell College

“Small Particles at a Small College: Research in Tau Lepton Physics"

Professor Daniel Aalberts

“Ultrafast Coherent Dynamics of Photoexcited Molecules, the First Step in Vision”
Massachusetts Institute of Technology

“Quantum Coherence in Photoexcited Polyenes”
American Physical Society March Meeting in Minneapolis

Professor Sarah Bolton,

“High Order Correlations in Semiconductor Nonlinear Optical Response”
March Meeting of the American Physical Society, G24, Minneapolis, MN, March 2000
(invited talk)

“High Order Exciton Correlations from Six-wave Mixing”
Quantum Electronics and Laser Science Conference, QThD5, San Francisco, CA, May 2000
(contributed talk) U. Neukirch, D. S. Chemla, V. M. Axt, L. J. Sham

Professor William Wootters

“Distributed Entanglement”
Isaac Newton Institute, Cambridge, England

“Atoms, Computers, and Multiple Worlds: A Further Leap in Cyberspace”
The Berkshire Atheneum, Pittsfield, MA

“Quantum Entanglement as a Resource for Communication”
New England Section Meeting, APS, Colby College

“Entangled Chains”
American Mathematical Society Meeting, Washington, DC
Northeast Section Meeting, AMS, Lowell, MA

Mark Acton	Teaching physics in Burkina Faso, Africa, with the Peace Corps.
David L. Adams	Teaching mathematics at Loomis Chafee School
Andy C. Chiu
Ginel C. Hill	Seeking employment in Chicago
Anthony M. Ndirango	Graduate study in physics, University of Cape Town, South Africa
Kevin M. O’Connor	Graduate study in computer science, University of Wisconsin
Matthew Scherer	Travel; then graduate study in political science
Andrew J. Speck	Graduate study in physics, Harvard University
Clayton A. Stein	Teaching in Austria
Qiang Sun	Working as a software engineer, Siebel Systems, San Mateo, CA

Rebecca T. Covers	Peace Corps in Senegal
Sara Kate May	Teaching at Riverdale School, New York
Kevin D. Russell	Fulbright Fellowship to Australia
Jason B. Slingerlend	Financial services, Colorado