PHYSICS DEPARTMENT

The Physics Department was delighted that the American Physical Society chose to honor Prof. William Wootters with its prize for Research in an Undergraduate Institution. The prize was given “for his pioneering work on quantum teleportation, his widely cited contributions to quantum information theory, and his prolific engagement of undergraduate students in this research at the foundation of quantum mechanics.” This was a banner year for Prof. Wootters who was also awarded the prestigious International Quantum Communications Award. The ceremony was held Dec. 2 in Tsukuba, Japan.

Photo: Jared Strait '07 and Tiku Majumder: laser beam power is less than 1 mW, so it was safe to work without goggles. Time-lapse photography makes the beam appear very bright.

As has been the case of late, many of this year’s senior physics and astrophysics majors decided to continue on to graduate school in physics, engineering or related subjects. Looking back at the classes of ’00 through ’04, we graduated 76 majors. Of these 30 are in science PhD programs, 5 in non-science PhD programs, 7 in science masters programs, 3 in non-science masters programs and two in professional programs. This is consistent with the recent trend that about half of our majors enroll in PhD programs, mostly in science. Some attend immediately after graduating, others take a year or two before applying. This year, between graduating seniors and other recent alums, we had 13 students applying for graduate school. They will be enrolling in PhD programs at MIT (1 plasma physics, 1 planetary science), MIT/Woods Hole (applied ocean science), Chicago (physics), Illinois (physics), Cornell (elect. eng.), Princeton (physics), U.C. Santa Barbara (physics), Davis (1 physics, 1 mech. eng.), U. Maryland (physics), CalTech (math) and Stanford (econ). Of course not all of our graduates decide to pursue an advanced degree and, as befits a liberal arts college, they fan out into a wide range of careers from finance to music. Many teach, at least for a while, and others work in industry, particularly computer related jobs.

This year, we have 19 students participating in our summer research program supported by generous college funding and outside grants. Student interest in this program remains high.

The National Science Foundation awarded associate Professor Daniel Aalberts a $260,819 grant for his proposal “Improving RNA Pseudoknot Models and Algorithms.” He was also awarded a $226,442 grant by the National Institute of Health for his proposal “Binding and Splicing mRNA.” He taught Seminar in Modern Physics (PHYS 151) and Statistical Physics (PHYS 302), and supervised four students in research topics ranging from RNA polymer physics to cancer statistics to animal foraging patterns.

Sarah Bolton taught Sound Light and Perception (PHYS 109) in the fall of 2006, to a group with interests ranging from art and music to biology and mathematics. In the spring of 2007, she was on sabbatical, and took part in a variety of research activities including chairing the Ultrafast Dynamics Committee for the Quantum Electronics and Laser Science Conference, which she attended in Baltimore in May. Bolton presided over the session on Ultrafast Spectroscopy of Quantum Wells. In April, she joined a small group representing Williams at the Conference on Tutorial Education at Lawrence University where she enjoyed presenting some of the successes of tutorial education in the sciences at Williams. Bolton added connections with other small colleges, performing an external review for the Physics Department at Lewis and Clark College in February. She also continued the research in her laboratory, in which a short-pulsed laser is used to measure very fast motions in semiconductors. This work is being extended in the summer of 2007 by Tom Derbish ’08, Fred Brasz ’09, and Dan King ’09.

With Williams College Chaplain Rick Spalding, Stuart Crampton, Barclay Jermain Professor of Physics Emeritus, continued to co-direct the North Berkshire Center for Religion and Science (NBCRS). NBCRS is funded by the Metanexus Institute as a Local Society. The purpose is to promote constructive discussions of the relationship of science to religion within the college and out in the local community. During 2006-2007 NBCRS sponsored a second monthly community seminar involving local clergy paired with scientists from their congregations. NBCRS also sponsored the April visit and talks by University of Nevada biologist Guy Hoelzer ’78. Crampton taught a Berkshire Institute for Lifetime Learning course on the relationship of science to religion and led a Forum at Berkshire Community College on Intelligent Design. Crampton continues to serve as a consultant to the Murdock Trust, a foundation supporting science in the five northwest states. He serves as a Director and chaired the Board of Directors of Research Corporation, America’s oldest science-related foundation during 2006 and 2007

Professor Kevin Jones continued his active collaboration with the internationally known research group at the National Institute of Standards and Technology (NIST) headed by Dr. William Phillips. Jones is in the process of making a transition between two research projects. For many years he worked on “photoassociation of ultracold atoms,” a process in which laser light is used to combine two slowly moving atoms to form a molecule. Last year he published a major review of the field in Reviews of Modern Physics. This led to speaking invitations this fall at an international meeting in Rochester, NY and the Harvard-MIT Center for Ultracold Atoms (where he saw Charlie Doret ’02, currently a graduate student at Harvard). Jones also chaired a meeting session on “New Approaches to Cold Molecules.”

Jones is currently working on a nonlinear optics experiment with Dr. Paul Lett. While the experiment still involves lasers and atoms, the atoms are not cold and the focus of the work is not on the atoms themselves but on the light that is emitted by the atoms. Using a process known as “four wave mixing” the apparatus produces “twin” beams of light that have a relative intensity noise below the standard quantum limit. Although the basic effect has been known for some time, the NIST group (including Colin McCormick ’95) has improved the performance to be competitive with the other known techniques for producing non-classical states of light. Kristen Lemons ’08 is joining the effort for a second summer and is currently exploring quantum imaging. She has been investigating the properties of non-classical twin beams of light that carry orbital angular momentum (in addition to the usual spin angular momentum associated with the polarization of light). Patty Liao ‘09, also at NIST for the summer, is working in a different research area (optical technology) investigating multispectral imaging techniques for medical applications. Patty and Kristen are supported by a grant from the NIST-SURF program. This Williams contingent is briefly joined by Nathan Hodas ’04, currently a graduate student at Cal Tech, who is a visitor in the same research group as Jones although working on a separate biological physics project.

During 2006-07, Prof. Tiku Majumder taught Particles and Waves – Enriched (PHYS 141) in the fall, and Electromagnetism and Modern Physics (PHYS 132) in the spring. He supervised the experimental work of three senior thesis students, Toby Schneider ’07, Owen Simpson ’07, and Jared Strait ’07. With funds from a new 3-year, $250,000 NSF research grant, Prof. Majumder hired postdoctoral fellow Dr. Mevan Gunawardena (Ph.D., Purdue Univ. 2007) who joined the group in December. Mevan worked closely with all three seniors as they completed their thesis research this spring.

During the summer of 2006, Prof. Majumder’s research group consisted of the three incoming thesis students plus rising junior Paul Hess ’08. Over the course of the summer, Jared and Paul designed, constructed, and tested the optical, electronic, and mechanics components of a new optical ‘wavemeter’ capable of measuring the wavelength of an unknown visible laser with one part-per-million accuracy. Toby continued the thesis work of Dave Butts ’07, focusing on the measurement of differential optical phase shifts induced by atoms in a three-mirror optical ring cavity, all now installed inside our atomic beam vacuum chamber. Owen resurrected a measurement technique originally developed by Chris Holmes ’03, which uses radiofrequency modulation of a laser signal, and subsequent lock-in detection to produce very high signal-to-noise ratio measurements of weak atomic absorption signals. All of this work continued efforts in the Majumder lab to make very high precision measurements of the atomic structure of heavy metal elements such as thallium and indium. These measurements test state-of-the-art calculations of atomic structure in these multi-electron atoms, and are useful in providing ‘table-top’ tests of fundamental physics of the sort normally associated with elementary particle theory and high-energy accelerators. Despite the substantial delay in the arrival of our new ‘blue’ diode laser system this year, all three Majumder lab students in the class of 2007 completed impressive and substantial honors theses. We wish Toby, Jared, and Owen the best of luck in their new endeavors next year! They will be pursuing, respectively: mechanical/ocean engineering (at MIT/Woods Hole); electrical engineering/optics (at Cornell); and physics (at Princeton).

This year, Majumder, as elected vice-chair of the Atomic Physics Gordon Conference, has been assisting in organizing this important summer professional meeting, and will be responsible for organizing the scientific program as conference chair in 2009. The summer of 2007 promises to be another active one in the Majumder lab, with rising senior Paul Hess ’08 returning to begin his senior thesis work, aided by rising sophomore Alec Crowell ’10. They plan to move ahead with spectroscopy in indium using the newly arrived ‘blue’ diode laser system.

Assistant Professor David Tucker-Smith was on sabbatical for the 2006-2007 academic year, during which he continued his research in particle theory. Tucker-Smith is exploring that we can learn from the Large Hadron Collider (LHC), due to begin running this coming year at CERN. In August of 2006 he participated in the Santa Fe workshop Particle Theory and the LHC. Tucker-Smith studied experimental signatures of extra quark doublets at the LHC With Witold Skiba of Yale University. In their study they demonstrated that distributions of the masses of individual jets can be used to discover heavier quark doublets than had been previously established in the literature. After completing that project, Tucker-Smith, in collaboration with Spencer Chang and Neal Weiner of NYU, began studying the cosmology and collider physics of a supersymmetric theory in which the dark matter particle is the scalar partner of the neutrino. In July, he will present some of their results at the SUSY 2007 conference in Germany. Zachary Thomas ’08 joined this project in June, 2007 and will continue to work on it towards his senior honors thesis. Tucker-Smith also started working with Tengjian Khoo ’09 and Michael Gerbush ’09 in June on LHC signatures for heavy scalars and gauge bosons coupled to the third-generation particles – top and bottom quarks and tau leptons.

Professor Jefferson Strait and his students have built, and are studying, an optical fiber laser that produces pulses of light about one picosecond 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. It lases at 1.55 microns, conveniently the same wavelength at which optical fiber is most transparent and therefore most suitable for telecommunications.

During the summer of 2006, Margaret Pigman ’07 and Krystle Barhaghi ’07 worked with Strait using the laser as a test bed for short pulses of light propagating in fiber. Building on mathematical models written by Aubryn Murray ’05 and Joseph Shoer ’06, Margaret and Krystle worked to refine our model describing pulse formation and propagation throughout the entire laser. Now that they have graduated, Margaret will teach math and physics in the Peace Corps in Kenya. Krystle has an internship at the National Institutes of Health.

Charles Cao ’09 joined Strait’s lab during the summer of 2007. He is conducting experiments measuring the polarization effects of optical fiber.

Strait served as pre-engineering advisor and continues to serve as department webmaster. He also served the college on the Committee on Academic Standing and served the town as a member of the Williamstown Finance Committee. Beginning in July of 2007, he will serve as College Marshal, the faculty member responsible for organizing the Convocation and Commencement ceremonies.

In the summer of 2006, Professor Bill Wootters worked with Jerry He ’08 and Daniel Sussman ’07 on two related projects in quantum information theory. Both projects were based on a discrete-phase-space representation of quantum states that had been developed in the theses of two previous honors students, Kate Gibbons ’03 and Matt Hoffman ’04. Jerry made a new connection between this phase-space representation and quantum computation. Daniel made use of the phase-space picture to find “minimum-uncertainty” quantum states. Daniel continued his work into the academic year as a thesis project that proved very successful and led to his being awarded Highest Honors. Wootters is beginning a new project in the summer of 2007 with two members of the class of 2008, Shelby Kimmel and Nathan Cook. The project has to do with quantum measurements performed on a pair of spatially separated objects and aims to estimate the amount of quantum communication needed in order to carry out such a measurement.

Wootters made trips to a few institutions and conferences this year. He visited St. Mary’s College of Maryland as a member of a team reviewing the college’s physics department, and he spent a week at Perimeter Institute in Ontario to meet with other researchers in quantum information theory. He gave talks at three conferences: the Feynman Festival at the University of Maryland, the Eighth International Conference on Quantum Communication, Measurement and Computation in Tsukuba, Japan, and the March meeting of the American Physical Society in Denver. In Japan, he received the 2006 International Quantum Communications Award, given biennially to researchers in that field, and at the APS meeting he was awarded the annual Prize for a Faculty Member for Research in an Undergraduate Institution.

Bryce Babcock, Staff Physicist and Coordinator of Science Facilities, continued his collaboration with Jay Pasachoff and Steven Souza on solar and planetary occultation research. He used their POETS CCD systems to observe the transit of Mercury from Sacramento Peak Observatory in New Mexico with Kevin Reardon ’92. He also observed a stellar occultation by Pluto from the Large Binocular Telescope Observatory in Arizona. (See the Astronomy News section for details.) In addition to his efforts developing research and instructional apparatus for the sciences, Babcock serves on the Animal Care, Safety, and Science Executive Committees. He also edits the Report of Science at Williams, the annual review of science activities at Williams, which is published in print and web accessible versions. (See <http://www.williams.edu/go/sciencecenter/center/sciwmspub.html>.)

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

Prof. Kevin Jones, Williams College

“Photoassociation: When Atoms Go Bump in the Light”
Prof. Christopher Monroe, University of Michigan

“Quantum Computing and Individual Atoms”
Dr. Douglas Martin, Brandeis University

“Structure and Function of Kinesin: A Fluorescent Look at a Molecular Motor”
Brian Gerke ’99, University of California, Berkeley

“Nearly Normal Galaxies in a Preposterous Universe”
Dr. Elizabeth Juarros, University of Connecticut”

“Polar Molecules in the Ultracold Realm”
Dr. Ana Jofre, National Institute of Standards and Technology

“HYDROSOMES: Optically Trapped Femtoliter Containers for Single Molecule Studies”
Dr. Andrew Skinner ’92, Skidmore College

“A Chain-Boson Model for the Decoherence of Coupled SQUIDS”
Prof. Ioana Niculescu, James Madison University

“Large Bjorken x: Convergence Point for High and Medium Energy Physics”
Dr. Noel Goddard, Harvard University

“Why This Genetic Code?”
David Park, Webster Atwell-Class of 1921 Professor of Physics, Emeritus, Williams College

“Complex-valued Probability?
Prof. Dayle Smith, Whitman College

“Modeling Electron Transfer Properties of Metalloproteins”
Prof. David Weiss, Pennsylvania State University

“ How To and Why Make a One-dimensional Gas”
Prof. Ward Lopes, Mt. Holyoke College

“The Development of Order in Ultra-thin PS-PMMA Diblock Copolymer Films”
Prof. Peter Collings, Swarthmore College

“Chromonic Liquid Crystals: A New Form of Soft Matter”
Ginel Hill ’00, Stanford University

“Investigating Gecko Adhesion with a MEMS 2-axis Force Sensor”

Kevin Jones

“Photoassociation: When Atoms Go Bump in the Light”
Joint Physics and Astronomy Colloquium, September, 2006

Daniel Aalberts

“Finding with Binding”
St. John’s University

“Asymmetry of RNA Pseudoknots: Observation and Theory”
Fairfield University

“Asymmetry and Abundance of RNA Pseudoknots”
Leiden University
Technical University of Munich
University of Cologne

“Splicing Messenger RNA”
Ludwig Maxmillians University in Munich
Kevin Jones

“Photoassociation Spectroscopy and the Study of ‘Physicist’s Molecules’”
A review at the Annual meeting of the Optical Society of America: Frontiers in Optics/Laser Science XXII, October 2006, Rochester, NY

“Photoassociation of Ultracold Atoms: Long Range States and Scattering”
A review at the Joint Harvard – MIT Center for Ultracold Atoms colloquium, October, 2006
Protik (Tiku) Majumder

“Diode Lasers, Heavy Atoms, and Tests of Fundamental Symmetries”
Department Colloquium, Old Dominion University, Norfolk, VA, March, 2007
Atomic Physics Seminar, University of Delaware, Newark, DE, April, 2007
David Tucker-Smith

“Using Jet Mass to Discover Vector Quarks at the LHC”
Boston University particle theory seminar, December, 2006

“Exploring the High-energy Frontier with the LHC”
Swarthmore College Physics Department Colloquium, April 2007

“Mixed Sneutrino Dark Matter at the LHC”
University of California, Davis Particle Theory Seminar, April, 2007
Fermilab Particle Theory Seminar, May, 2007
William Wootters

“Discrete Phase Space and Minimum-Uncertainty States”
Feynman Festival, College Park, MD, August 2006
8^th International Conference on Quantum Communication, Measurement, and Computation, Tsukuba, Japan, Dec. 2006
Perimeter Institute, Waterloo, Ontario, March 2007
William Wootters, continued:

Picturing Qubits in Phase Space”
Meeting of the American Physical Society, Denver, March 2007