PHYSICS
DEPARTMENT
The fall Convocation ceremonies celebrated the completion of the new
Science Center. A group of distinguished scientists was invited to receive
honorary degrees. In addition to the usual ceremonies, each of the honorees
presented a lecture describing his or her research. These lectures gave a fine
sense of the breadth and vitality of the scientific enterprise as Williams
dedicated this marvelous new facility. Two honorees were of particular interest
to the Physics Department. The first, Prof. Daniel Kleppner ’53 of MIT,
is one of the leading figures in the atomic Physics community. His
provocatively titled talk “The First Two Hundred Years of Quantum
Mechanics” stimulated a lively discussion and provided a fitting capstone
to the lecture series. In addition to participating in the official activities,
Prof. Kleppner was kind enough to present lectures to two physics classes and to
meet informally with students. The second honoree of particular interest to the
department was Prof. Jocelyn Bell Burnell of the Open University (UK). She gave
a lively and engaging talk describing the twists and turns along the path that
led to her discovery of pulsars.
The renovation of the Thompson Physical Laboratory, the final step in the
creation of the Science Center, was completed a few months after the official
opening. The move back into the nicely renovated spaces went surprisingly
smooth. Although there were some close calls, we were able to offer our popular
lab-based Winter Studies in Holography and Electronics even as workers completed
the last installation of electric outlets, etc. The second floor space formerly
housing the library has been transformed into the spacious David Park
Laboratory. This room and the corresponding lab on the third floor provide us
with greatly improved space for introductory teaching labs. On the first floor,
we were able to clear out some old partitions and create a very nice student
common room. Outfitted with library-style furniture, this room provides an
inviting space for students to gather to study quietly or discuss physics
problems at the blackboard. Our twice-weekly student/faculty “teas”
are held here. We are very pleased that the informal student-student and
student-faculty interaction so central to our program has been encouraged and
supported by the new space.
While building matters occupied much of our attention for the year, we also
carried out the important task of searching for a new tenure track assistant
professor. Although the overall number of applicants was down from a few years
ago (a healthy sign for the profession), we continue to attract strong
candidates looking for the particular balance of teaching and research that
Williams offers. Joining us July 1 will be Dr. Dwight Whitaker currently a
post-doc at the University of Colorado. He is presently working on atomic
physics techniques for producing Bose-Einstein condensates of dilute atomic
gasses. His thesis work was in more conventional low temperature experiments so
he brings a wide range of interest and skills to the department.
Assistant Professor Daniel Aalberts was on sabbatical leave the 2000-2001
academic year. In the fall, he was a visitor at the Center for Studies in
Physics and Biology at Rockefeller University where he collaborated with Eric
Siggia on RNA folding and modelling gene chip kinetics. That work continued
through the spring and will involve summer students Kristina Weyer ’03 and
Mike Baiocchi ’03.
Aalberts also actively supervised student research projects on campus.
Thesis student Ben Cooper ’01 studied how the optical properties of
polyenes (molecules with multiple double bonds) respond to being mechanically
stretched. Fritz Stabenau ’02 investigated structural transitions of
polyenes. John Parman ’02 simulated lipid bilayer dynamics, and Rachel
Horwitz ’03 studied the shapes of folded proteins.
With the “Diminished Faculty”, a quartet of science faculty,
Aalberts performed to alumni groups and classes.
In 2000-2001, Assistant Professor Sarah Bolton taught PHYS 301,
Introduction to Quantum Mechanics in the fall. In the spring, she taught
PHYS 142, Physics Today, as well as PHYS 451, Solid State Physics.
With Lee Park of the Chemistry department, Bolton organized the “Bernhard
Science Symposium” which brought ten prominent women scientists to campus
to present their work on January 24-25, 2001.
Prof. Sarah Bolton and Ricky Joshi at work with the Titanium
Sapphire laser.
During 2000-2001, Bolton worked with Ricky Joshi ’01 in studies of
semiconductors using 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. They are using the laser to determine how these very fast motions
are altered when the electrons in a material are confined to two dimensions.
Work on this project will continue in the summer of 2001 with students Mark
Burkhardt ’04 and Alex Glenday ’02.
The department is pleased to note that Prof. Bolton successfully passed
through the tenure process this fall and will be promoted to associate professor
as of July 1, 2001.
Professor Stuart Crampton continued his research into the implications for
religion of modern science and designed a course on that subject to be taught in
the spring of 2001. He continues to serve on the Board of Directors of Research
Corporation and as a consultant to the Sherman Fairchild Foundation Scientific
Equipment Program and the Academic Excellence study of the role of research in
the natural sciences at undergraduate institutions.
Department Chair and Professor of Physics Kevin Jones returned from a two
year sabbatical at the National Institute of Standards and Technology in
Gaithersburg, MD. Jones has a long-standing research collaboration with the
Laser Cooling and Trapping Group there headed by Dr. William Phillips. This
group pioneered techniques for using lasers to produce samples of very cold
atoms (<1/1000 degree above absolute zero). Among the many interesting
scientific opportunities opened by the development of these cooling techniques
is the ability to produce translationally cold molecules by photoassociating two
atoms. Working with Dr. Paul Lett and other NIST staff, Jones and his students
have used this photoassociation process to study molecules in states difficult
to assess by other means. From the details of the molecular spectra one learns
not only new information about the molecules, but also about the properties of
the constituent atoms and the nature of the collisions between atoms at these
very low temperatures.
Recently Jones and colleagues showed that application of light tuned near a
photoassociation resonance can dramatically alter the collision properties of
atoms through the formation of a so-called “optical Feshbach
resonance.” This process had been discussed theoretically but had not
previously been observed. One of the “hottest” areas in atomic
physics is the study of Bose-Einstein condensates: gasses of atoms cooled so low
that they all fall into the lowest possible quantum state. The collisional
properties of the atoms play a central role in understanding the properties of
the condensate. Much of Jones’s recent work has been directed towards
making accurate measurements of these collisional properties. There is
speculation that optical Feshbach resonances recently observed by Jones will be
useful in manipulating the properties of condensates. Jones also participated
in an experiment to measure the rate of photoassociation in condensate. In
agreement with theory, the rate can be surprisingly high despite the very low
velocity of the atoms.
In the fall, Jones traveled to Graz, Austria to describe some of this work
at the Workshop on Prospects of Cold Molecules II. At the annual meeting
of the American Physical Society Division of Atomic Molecular and Optical
Physics, held this year in London, Ontario, Jones presented some new results on
the formation of cold molecules. Along with Sarah Iams ’04 he will be
returning to NIST this summer to continue this work.
During the summer of 2000, Assistant Professor Protik Majumder supervised
three students in the summer research program. Andrew Speck ’00 stayed on
for the summer to continue his thesis work before leaving to begin a Ph.D.
program in Physics at Harvard. Andrew was joined by incoming thesis student,
Paul Friedberg ’01, and rising junior Charlie Doret ’02. These
students worked closely with current postdoctoral associate Dr. David Richardson
on the current atomic thallium spectroscopy experiments. During the month of
June (2000), the group moved the Majumder lab into the new Laser Facility in the
basement of Bronfman, and then presented a poster at the 2000 meeting of the
Division of Atomic Molecular and Optical Physics (DAMOP) of the American
Physical Society in Storrs, CT.
During the 2000-01 academic year, Majumder taught PHYS 141, Particles
and Waves - Enriched, the tutorial, PHYS 402T, Topics in Quantum
Mechanics, and PHYS 400, Thermal and Statistical Physics. He and
Prof. Bolton jointly taught an Electronics course during WSP, the first
departmental course offering in the brand new David A. Park teaching lab. Prof.
Majumder also served as the liaison to the Society of Physics Students
group.
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. Paul Friedberg ’01 completed a thesis this year
entitled “Measuring the Stark Shift in the
6P1/2-7S1/2 378nm Transition in Atomic Thallium”.
Building on the work of previous thesis students, Paul was able to obtain our
first atomic beam thallium spectra. This involved substantial work in
frequency-stabilization, frequency-doubling, and tuning of the laser system.
Equally important, it involved final development and testing of the atomic
thallium beam apparatus and the vacuum system. As expected, the beam spectra
show an order-of-magnitude improvement in resolution compared to the UV spectra
obtained in the vapor cell. (The latter was described in a July 2000 Phys.
Rev. A article by Richardson, Lyman ’99, and Majumder). Paul also
obtained and analyzed the first data to measure the Stark shift by the method
developed in our group, involving simultaneous application of a very large,
well-known electric field, and an acousto-optic-modulator driven laser frequency
shift. The department has nominated Paul for the national Apker Award, given
annually by the American Physical Society for the best undergraduate thesis
research project. Postdoc David Richardson worked with Paul on various aspects
of this project, and pursued work on our other NIST-funded time-reversal
violation experiment. In this latter experiment, a high-finesse optical ring
cavity is being designed for use with an infrared 1283 nm diode laser, which
will eventually be incorporated into the atomic beam apparatus.
In June 2001, Charlie Doret ’02 officially began his thesis work,
and, joined by rising sophomore Elliot Morrison ’04, will continue both
the Stark shift work and the NIST experiment development work. Finally, with
some regret, and best wishes for the future, we bid farewell to postdoc David
Richardson who will be taking a teaching job in Oklahoma City, OK beginning in
July 2001. We thank David for his valuable contributions to the work, for his
effective supervision of many undergraduates, and for his generous and friendly
presence in the lab.
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, in the fall term and was on sabbatical leave in the spring
term. He served as a member of the Executive Board of the New England Section
of the American Physical Society, attending section meetings at Central
Connecticut State University and at Middlebury. He also attended the Conference
on Lasers and Electro-Optics held in Baltimore in April.
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,
conveniently the same wavelength at which optical fiber is most transparent and
therefore most suitable for telecommunications. During the summer of 2001, John
Spivack ’02 has joined Strait to continue that work. The eventual goal is
to study how these short pulses propagate in optical fiber.
Professor William Wootters supervised two thesis students this year, Ken
Dennison and Duane Lee. Both made new contributions to our understanding of
quantum entanglement, a phenomenon that underlies much of the recently proposed
technology known as quantum information processing. Ken’s work, which
explores the physical limits on multiparticle entanglement, has already been
presented off campus at a conference on quantum information held at Rochester
University. Wootters also supervised two sophomores, Kate Gibbons and Sarah
Nichols, in independent projects over the winter study period. Kate studied the
interpretation of quantum mechanics while Sarah did research on alternative
definitions of entropy.
In addition to teaching the standard courses PHYS 131,
Particles and
Waves, and PHYS 210,
Mathematical Methods for Scientists, Wootters
co-taught with Prof. Susan Loepp of the Mathematics Department a new course,
MATH/PHYS 316,
Protecting Information: Applications of Abstract Algebra and
Quantum Physics. Development of the course, which includes topics of
current research such as quantum cryptography and quantum computation, was
supported by a grant from the National Science Foundation. In the coming
months, Loepp and Wootters will be polishing their lecture notes and other
course materials for use at other institutions, particularly Vassar College and
Denison University where faculty members are already planning to teach the
course. The course materials are all currently available at
http://www.williams.edu/williams-only/crypto/.
Staff Physicist and Coordinator of Science Facilities, Bryce Babcock,
collaborated with Professor Jay Pasachoff on observations of the total solar
eclipse in Lusaka, Zambia in June 2001. (For further details regarding these
experiments and other publications, see the Astronomy departmental and faculty
publications sections.) In addition to his work preparing for the eclipse and
developing other research and instructional laboratory apparatus for the
sciences, he continues to edit the annual Report of Science at Williams. With
the conclusion of the Science Building Project in the fall, his work on the
Science Building Committee has come to an end - even though portions of this
project seem to continue indefinitely. However, he has had no lack of
involvement with construction, since he has been building committee chair and
“clerk of the works” for the building program at Williamstown
Community Bible Church during the past year. This project is nearly complete,
with the new building having opened for use June 17, 2001.
Visiting Assistant Professor Paul Weber, formerly at Grinnell College,
joined us for the year. Weber ably taught an electricity and magnetism course
for sophomores and the second half of the premedical physics course. We wish
him well in his future endeavors.
Class
of 1960 Scholars in Physics
Gabriel Brammer
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Duane Lee
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Benjamin Cooper
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John Parman
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Kenneth Dennison
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Daniel Schwab
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S. Charles Doret
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Daniel Seaton
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Caleb Fassett
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Joey Shapiro
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Paul Friedberg Jeffrey Garland Alexander
Glenday David Glick
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Matthew Silver Andrew Sullivan David
Ticehurst Darik Vélez
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PHYSICS COLLOQUIA
[Colloquia are held jointly with Astronomy. See Astronomy
section for additional listings.]
Professor Timothy Halpin-Healy
Barnard College
“Extremal Paths in a Random Energy Landscape”
Professor
Priyan Dias
University of Moratuwa, Moratuwa, Sri Lanka
“Constructing a Philosophy of Engineering”
Dr. Alexander D.
Cronin
M.I.T. - Cambridge, MA
“Atom-Beam Interferometry and the Transition from Quantum to
Classical Behavior”
Class of 1960’s Scholars program
Professor David S. Citrin
’85
Washington State University
“How Fast Can Semiconductors Emit Light? Exciton Polaritons in
Low-Dimensional Systems”
Class of 1960’s Scholars
Program
Professor Frank Moscatelli
Swarthmore College
“NIST F2 - The Cesium Fountain Atomic Clock”
Class of 1960’s Scholars Program
Professor William
Wootters
Williams College - Physics Department/Computer Science
Department
“Computing in Parallel Worlds: The Quantum Search
Algorithm”
Professor John Krupczak
Hope College - Holland,
MI
“Demystifying Technology: Using Consumer Products to Explain Some
Principles of Physics”
Class of 1960’s Scholars Program
Dr. Michael I. Larkin
Columbia
University
“Unconventional Superconductors: How Many Ways Can Electrons Avoid
the Pauli Exclusion Principle?”
Dr. Philip Collins
IBM - T.J. Watson
Research Center
“Carbon Nanotube Electronic Devices”
Dr. Janice
Hudgings
Mount Holyoke College
“Vertical-Cavity Surface Emitting Lasers: A Bright Idea”
Dr.
Dwight Whitaker
University of Colorado - JILA
“The People’s BEC: Towards a Bose-Einstein Condensate for the
Masses”
Dr. David DiVincenzo
IBM Watson Research Center
“Prospects for the Physical Implementation of Quantum
Computation”
Class of 1960’s Scholars Program
Professor Jay Lawrence
Dartmouth College
“Nonexponential Decay and Quantum Measurement
Paradoxes”
Class of 1960’s Scholars Program
Dr. Chad
Orzel
Yale University
“Squeezed States in a Bose-Einstein Condensate”
Dr. James
Lerczak
Woods Hole Oceanographic Institution
“Oceanic Internal Waves: From Internal Tides to Internal
Surf”
Dr. Daniel Butts
Harvard Medical School
“How Does Early Activity in the Retina Guide Brain
Development?”
OFF-CAMPUS PHYSICS PRESENTATIONS
Professor Daniel
Aalberts
“Ultrafast Photoisomerization: The First Step in
Vision”
Colgate College
“A Simple Scenario for Ultrafast
Photoisomerization”
Rockefeller University
Professor Sarah Bolton,
“High Order Correlations in Semiconductor Nonlinear Optical
Response”
Invited talk at November Meeting of the Materials Research
Society, Boston, MA - November 2000
“Sixth-order Coulomb Correlations
Identified in a Semiconductor Single Quantum Well”
Quantum Electronics
and Laser Science Conference, Baltimore, MD - May 2001 (invited talk)
“Ultrafast Spectroscopy of Nanostructures: Windows into Many-Body
Interactions”
Dartmouth College - Condensed Matter Seminar - October 15, 2000
“Squeezing Semiconductors: What Ultrafast Measurements Tell Us about
Mesoscopia”
Mt. Holyoke College - Physics Department Colloquium - November 20,
2000
“Squeezing Semiconductors: What Ultrafast Measurements tell us about
Mesoscopia”
Amherst College - Physics Department Colloquium - March 5,
2001
Professor Kevin Jones
“Hyperfine Structure of High Lying Vibrational Levels in the
Na2 1g (3S+3P3/2) State Observed by
Photoassociation of Cold Atoms” (with Ginel Hill ’00 and
others)
Meeting of the American Physical Society Division of Atomic Molecular
and Optical Physics, Storrs, CT
“Observation of Na2 gerade Levels Dissociating to
the 3P+3P Atomic Limit by Two-color Photoassociation Spectroscopy” (with
F. Fatemi and P. D. Lett)
Meeting of the American Physical Society Division
of Atomic Molecular and Optical Physics, Storrs, CT
“Ultracold Atom Collisions Probed with Short Laser Pulses”
(with F. Fatemi and P. D. Lett)
Meeting of the American Physical Society
Division of Atomic Molecular and Optical Physics, Storrs, CT
“Photoassociation Spectroscopy of MilliKelvin Sodium Atoms”
(with F. Fatemi and P. D. Lett)
Workshop on Prospects of Cold Molecules II,
Schloss St. Martin, Graz Austria
“Observation of Optically Induced Feshbach Resonances in Collisions
of Cold Atoms” (with F. Fatemi and P. D. Lett)
Workshop on Prospects of Cold Molecules II, Schloss St. Martin, Graz
Austria
“The Hot and Cold Show”
Williamstown Elementary School (Third grade Science Night, Ms.
Bucky’s 5th grade class and Mrs. Simon’s Kindergarten
class)
“Production of Translationally Cold Na2 Molecules in High
Vibrational Levels of the Triplet Ground State”
Meeting of the American Physical Society Division of Atomic Molecular and
Optical Physics London, Ontario
May 2001
Professor Protik (Tiku) Majumder
“Diode Lasers, Thallium Atoms, and Tests of Fundamental
Physics”
College of the Holy Cross (department colloquium), June 27, 2000
“Precise Atomic Structure Measurements in Thallium at 378 nm Using a
Frequency-doubled Diode Laser”
APS Division of Atomic, Molecular, and Optical Physics Meeting (contributed
talk), London, Ontario, CA, May 15, 2001
Professor William Wootters
“Quantum Entanglement as a Resource for
Communication”
University of Texas at Austin, University of Virginia, SUNY Stony Brook
Max Planck Symposium, University of Puget Sound
“Sharing Entanglement”
University of New Mexico/Los Alamos Joint Seminar
International Conference on Quantum Information, University of
Rochester
“Sending Classical Bits through Quantum Channels”
Dartmouth College
ON-CAMPUS PHYSICS PRESENTATIONS
Professor Daniel Aalberts
“Phase Transitions and Renormalization Group Theory”
Summer research program - summer 2000
Professor Protik (Tiku)
Majumder
“Diode Lasers, Thallium, and the Next Decimal Place”
Summer Science Lecture Series, June 27, 2000
Professor William
Wootters
“Why Things Fall”
Physics Department Summer Seminar
“Are Quantum Particles Monogamous”
Bronfman Lunch Talk
POSTGRADUATE PLANS OF DEPARTMENT MAJORS
Jonathan B. Briggs
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Applying for high school teaching position
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Benjamin K. Cooper
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Seeking employment
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Paul D. Friedberg
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Ph.D. program in Electrical Engineering at Stanford
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Ricky Joshi
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Masters program in engineering at Dartmouth
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Ryan E. Kurlinski
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Seeking employment
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Andrew P. Sullivan
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Seeking employment
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ASTROPHYSICS
Misa M. Cowee
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Graduate School in Planetary Science at UCLA
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Kenneth A. Dennison
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Graduate School in physics at Cornell
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Joel M. Iams
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Marine Corps Officer Candidate School
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Duane Lee
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Working; preparing for graduate school application
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Daniel B. Seaton
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Working on solar satellite data at Harvard-Smithsonian Center for
Astrophysics
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Joey R. Shapiro
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Preparing for Graduate School application; teaching in
Switzerland
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Matthew R. Silver
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Master’s program at International Space University, Strasbourg,
France
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Darik O. Vélez
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Teaching at Westminster School, Connecticut
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