The Physics Department has had a very exciting year. The American Physical Society presented Christopher Chudzicki’10 with the annual Leroy Apker Award for outstanding American undergraduate research. Williams Physics has won four of the past twelve Apker Awards, an amazing and unprecedented achievement.

A Fall 2010 external visiting committee described the Physics Department as “one of the top physics programs in the Nation” and “one of the most brilliant jewels of Williams College.” Another remarked, “It is not a coincidence that year after year Williams College is the top choice for a disproportionately large number of high school seniors who want to major in physics. The Department of Physics at Williams College offers one of the very best undergraduate programs in the country.”

Thirteen Physics and Astrophysics majors graduated in June.  Seven are starting graduate work in science or engineering this fall. Others plan to work as a NYC teaching fellow, a lab instructor at Williams, a research technician at Raytheon, and an analyst at Bain & Company, proving again that physics is a great preparation for many professions.

The Physics and Astronomy colloquium program was excellent this year, headlined by Nobel Laureate Steven Weinberg’s presentation “The Dark Side of the Universe.” We were also delighted to have four alumni (Brian Wecht ’97, Justin Brown ’05, Ned Ladd ’86, and Laura Brenneman ’99) return to give presentations and to meet with students to talk about the paths they’ve taken in their careers.

Finally, the Department is excited to welcome Visiting Assistant Professor Michael Seifert who will join us during Sarah Bolton’s term as Dean of the College, Administrative Assistant Michele Rech, Assistant Lab Instructor Tony Lorenzo’11, and Postdoctoral Research Fellow Gambhir Ranjit.

In the Aalberts Lab, thesis students Jeff Meng’11 created a polymer-physics model for stretched loops related to small RNA-mRNA binding and Becca Sullivan’11 described the importance of including thermal fluctuations around consensus RNA structures. He also worked with Scientific Programmer Bill Jannen ’09 on an algorithm to cluster related RNA structures. Collaborations with Joel Clemmer’12 and Julian Hess’13 begin this summer.

Emeritus Professor Stuart Crampton presented some ideas about how physics may suggest ideas about God to a forum at a local church and followed that up in an article in the student publication Telos. He continues to serve as a scientific consultant to the Murdock Trust, a foundation supporting science in the five northwest states, and is an Emeritus Director of Research Corporation, America’s oldest foundation devoted exclusively to science.

Professor Kevin Jones coordinated a successful grant application to the Summer Undergraduate Research Fellowship program of the National Institute of Standards and Technology (NIST). The grant is supporting two students, Christina Knapp’13 and David Kealhofer’13, to do research at the Gaithersburg Maryland NIST campus for 11 weeks during summer 2011. In addition, Jones has a separate grant enabling him to be a Guest Researcher at NIST. Jones and the two students are working with Dr. Paul Lett in the Laser Cooling and Trapping Group headed by Dr. William Phillips. They are building a diode laser system to produce light suitable for interacting with cesium atoms. If all goes well, they will be using the non-linear optical properties of cesium atoms to modify the laser light and produce non-classical, quantum entangled, beams of light. This work, if successful, will extend the NIST group’s previous scheme for “twin beam” generation in atomic vapors to a new wavelength regime. As a side project, Christina and David are designing a magnet for use in a quantum memory experiment.

In addition to the project with the two students, Jones is also working with post-docs and graduate students at NIST on other projects begun during prior visits to NIST. All of the work is related in one way or another to producing and manipulating non-classical states of light. Such states are of interest for quantum information processing and enhanced imaging techniques. Jones and his colleagues are preparing a manuscript describing their recent results on single beam “squeezed vacuum” produced by a non-linear interaction between light and Rubidium atoms. In the lab they are working to extend these initial results to construct and characterize a “noiseless” image amplifier.

Research in Assistant Professor, Ward Lopes’s lab continued with the themes of studying the self-assembly of organic molecules and using holographic control of light for micromanipulation.

Leah Hurwich’11 continued work begun by Scott Olesen’10 to investigate a common assumption that the microscopic mechanisms by which materials become more ordered depend only upon the fundamental symmetries of the material in question. Both Leah and Scott studied a class of organic molecules, which self-assemble to form stripes. Defects in the striped pattern are free to move when the sample is heated and they tend to annihilate in order to reduce the energy of the sample. The mechanisms by which defects in striped samples annihilate are well studied and it is believed that all striped samples behave the same way. Scott, however, observed many annihilation events, which run counter to the previously observed annihilation mechanisms. Leah’s data also came to the same conclusion.

On the optical side of the lab, Peter Gottlieb’11 continued Joseph Skitka’s’10 work investigating algorithms for calculating phase-only holograms. Holographic Optical Trapping (HOT) is a method for optical micromanipulation. For various historical and practical reasons, the holograms used in HOT use only the phase degrees of freedom of the light used in optical micromanipulation. This greatly increases the difficulty and time to calculate appropriate holograms. Joe discovered and numerically tested a couple of algorithms which give improved theoretical performance in less computational time than well established algorithms used for calculating phase only holograms. Peter tested and characterized how well these algorithms operate in a laboratory environment as part of his thesis work. Peter was awarded Highest Honors in Physics for his thesis.

This summer Ward starts his Assistant Professor Leave. During his sabbatical, he will travel to the University of Illinois at Urbana-Champaign to work on imaging problems in Biophysics, which use holographic techniques. With the balance of his time, he will be working in his lab in Williamstown to finish off the projects started by the students in his lab.

During the 2010-2011 academic year Professor Tiku Majumder began his term as Director of the Science Center and Chair of the Science Executive committee. In his administrative role, he has supervised and supported faculty research funding, the student research program, as well as numerous projects related to facilities, development, and admissions, which relate to the Science Center. He also taught Quantum Mechanics, PHYS 301, and its associated advance laboratory, to a record number of 23 students in the fall of 2010. He continued to pursue diode laser and atomic physics experiments in his research lab, teaming up with senior thesis student Antonio (Tony) Lorenzo’11, and newly hired post-doc Dr. Gambhir Ranjit. Gambhir was hired with funds from Majumder’s new $300,000 NSF grant which will also supports purchase of numerous new pieces of scientific equipment over the next three years.

The Majumder lab continues to pursue very high precision measurements of 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. Two recent senior thesis students, Charles Cao ‘09 (now at Princeton) and Paul Hess ’08 (now at Harvard) helped to complete the group’s first spectroscopy experiment in indium, using a stabilized 410 nm diode laser and a sealed, heated quartz vapor cell. This work was published in the journal Physical Review A, with these students as co-authors. Tony Lorenzo is now using this same laser system to study indium in the confines of a high-vacuum chamber by producing a high-flux atomic beam of indium. Tony, with help from our new model-maker, and design engineer Michael Taylor, designed, tested and installed a new source oven capable of reaching 1000 degrees C under vacuum. Using a very sensitive frequency-modulation spectroscopy technique, he has measured, for the first time, absorption signals in the atomic beam environment, demonstrating the feasibility of this experiment.

Incoming thesis student Andy Schneider’12 will build upon Tony’s work, and complete an atomic beam measurement of the Stark shift (by applying electric fields of 30,000 V/cm to the atoms) in indium beginning in June 2011. Andy will be joined this summer by Taryn Siegel’12, who will be working on thallium spectroscopy using a UV diode laser, and Nathan Schine’13 who has already spent a very productive WSP month working in the Majumder lab. Finally, Prof. Majumder will be giving an invited talk and serving as a discussion leader at this year’s biennial Atomic Physics Gordon Research Conference at the end of June.

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 acts 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. This laser functions as a test bed for short pulses of light propagating in fiber.

During the summer of 2010 Takuto Sato’12 and Nathaniel Lim’11 worked with Strait testing the laser and refining a model describing pulse formation in it. The polarization of light in the laser cavity plays an important role, so they carefully measured the transmission of the laser cavity as a function of polarization. Nathaniel continued to work with Strait during the academic year and wrote his honors thesis on these experiments.

During the fall semester Strait taught 108, Energy Science and Technology for the third time. This course aimed to give non-natural science majors a quantitative approach to issues in energy supply and use. After an introduction to some basic physical principles, the course covered electric power generation (fossil fuels, nuclear, photovoltaic solar cells, wind turbines), transportation (internal combustion engines, electric cars, hybrid cars, hydrogen fuel cell cars) and energy efficient building technologies.

Strait serves as pre-engineering advisor, department webmaster, and College Marshal, the faculty member responsible for coordinating the Convocation and Commencement ceremonies. In September 2010 Strait organized the induction of Adam Falk as the College’s new president.

Assistant Professor, Frederick Strauch continued his theoretical work in superconducting quantum circuits, quantum algorithms, and other applications to quantum information processing. His recent work on quantum routing with Chris Chudzicki’10 (now at MIT) was published in Physical Review Letters, one of the top journals in physics, and Chris’s senior thesis was honored by the national Leroy Apker Award for undergraduate achievement in physics from the American Physical Society (APS). Chris presented his work at a special invited talk at the APS March Meeting in Dallas, where fellow research Steven Jackson’10 (now at Princeton) also contributed a talk based on his senior thesis.

The quantum routing research was supported by a grant from the Research Corporation for Science Advancement, and was continued in the summer of 2010 with Praphruetpong (Ben) Athiwaratkun’12 and Qiao Zhang’13. Ben verified theoretical predictions for quantum routing with decoherence, while Qiao developed a method to visualize the dynamics of quantum state transfer.

Strauch continued collaboration with Kurt Jacobs at the University of Massachusetts Boston to study quantum control and measurement of superconducting resonators using high-performance parallel computing. Their first work was published in Physical Review Letters, in collaboration with Ray Simmonds of the National Institute of Standards and Technology, and is now supported by a continuing grant of $233,186 from the National Science Foundation. This work was continued during 2010-2011 year by independent research by Douglas Onyango’11 (who is heading to Columbia University next year). Finally, Samyam Rajbhandari’11 completed a senior honors thesis on decoherence and encoding of quantum walks, and will be studying computer science at Ohio State University next year.

Strauch taught PHYS 411 in Fall semester 2010, an advanced tutorial on Classical Mechanics, for which he developed a number of new computer simulations. In Spring semester 2011, he taught PHYS 132, Electromagnetism and the Structure of Matter, the second of the department’s introductory physics sequence for non-majors, for which he incorporated the PhET physics simulations developed by Nobel Prize physicist Carl Wieman. This latter was inspired by a workshop he attended in Summer semester 2010 by the American Association of Physics Teachers on innovations in undergraduate teaching of physics.

During the 2010-2011 academic year, Associate Professor David Tucker-Smith was on sabbatical as a visiting researcher at NYU’s Center for Cosmology and Particle Physics and at the Institute for Advanced Study at Princeton. Tucker-Smith collaborated with colleagues on projects in theoretical particle physics, focusing on how models can be tested at Fermilab’s Tevatron and at the Large Hadron Collider. Tucker-Smith also participated in the workshop embarking on a New Era of Discovery: LHC, dark matter, and their interplay, at the Berkeley Center for Theoretical Physics, and reviewed proposals for NSF.

In the summer of 2011 will work with Dylan Gilbert’13, Murat Kologlu’12, and Margot Robinson’12 on particle physics models and their experimental signatures. Murat and Margot will continue their research during the academic year as senior honors thesis students. In the fall semester of 2011 Tucker-Smith will teach Newton, Einstein and Beyond (PHYS 107), a course intended for non-scientists, and in the spring semester he will teach Mathematical Methods for Scientists (PHYS 210), and an introduction to Einstein’s general relativity, Gravity (PHYS 418).

Professor Bill Wootters worked this year with Antoniya Aleksandrova’11 on a project investigating a version of quantum mechanics based on real numbers instead of the usual complex numbers. They found that the real-number theory agrees with ordinary quantum mechanics in a certain limit but that the two theories diverge subtly from each other as one moves away from the limiting case. It remains for future research to determine how one might test the alternative theory experimentally. In the summer of 2011 Prof. Wootters will work with Victoria Borish’12 and Roshan Sharma’13.

Prof. Wootters participated in a few conferences this year, including the American Physical Society’s March meeting, where he was pleased to attend talks by a number of former students. He gave the keynote address at a meeting of the Anacapa Society, an organization that supports research in theoretical physics at undergraduate institutions.

Class of 1960 Scholars in Physics

Department Colloquia

[Colloquia are held jointly with the Astronomy Department.]

Prof. Sarah Demer, Yale University

“Hunting for New Physcis with CERN’s Large Hadron Collider”

Prof. Courtney Lannert, Wellesley College

“Studying Quantum Dynamics with Ultracold Atomic Gases”

Prof. Pan Li, University of Albany
“Effect of Mg2 Ions on Mechanical Unfolding of a Hairpin”

Prof. Luis Orozco, University of Maryland

“Grand State Quantum Beats”

Prof. Ophelia Tsui, Boston University

“Glass Transition Temperature of Polymer Films”

Dr. Brian Wccht ’97, University of Michigan
“Supersymmetry as a Theoretical Toolbox”

Dr. Meg Schwamb, Yale University

“The Solar System Beyond Sedna”

Justin Brown ’05, Princeton University

“A New Limit on Lorentz – and CPT – Violating Neutron Spin Interactions”

Prof. Bill Wootters, Williams College

“Physics in Rwanda ”

Prof Ned Ladd ’86, Bucknell University & Harvard /Smithsonian Center for Astrophysics

“Why aren’t There More Stars? The Battle Against Gravity in our Galaxy’s Nurseries ”

Dr. Laura Brenneman ’99, Harvard/Smithsonian Center for Astrophysics

“Spinning Black Holes”

Prof. Graziano Vernizzi, Siena College

“RNA Folding and Random Matrix Theory”

Prof. Steven Weinberg, Nobel Laureate, University of Texas

“The Dark Side of the Universe”

Prof. Steven Girvin, Yale University

“The Race to Build a Quantum Computer”

Other on Campus Presentations

Frederick Strauch

“From cuckoos to qubits: Quantum Computing by Exciting Oscillators”
Summer Science Program Talk, Williams College (July 20, 2010)

Bill Wootters

“Keeping It Real: Quantum Mechanics without Complex Numbers”
Bronfman faculty lunch talk, November 9, 2010

Off-Campus Colloquia

Daniel P. Aalberts

“RNAbows: an intuitive tool for visualizing RNA structures”
poster presentation at the Biology of Post-Transcriptional Gene Regulation Gordon Research Conference (with Bill Jannen ’09)

Tiku Majumder

“Precise Measurement of the Stark Shift within the 5P_1/22-6S_1/2 Transition in Indium -115”
poster presentation at Division of Atomic, Molecular, and Optical Physics conference, Atlanta, GA (with Antonio Lorenzo’11 and Gambhir Ranjit, Post-doc)

Frederick Strauch

“Arbitrary Control of Entanglement between Two Superconducting Resonators”
QUEST Workshop sponsored by Los Alamos National Laboratory, Santa Fe, NM (August 23, 2010)

“Arbitrary Control of Entanglement between Two Superconducting Resonators”
Bits and Waves Laboratory Seminar, BBN, Cambridge, MA (September 30, 2010)

“Quantum Logic Gates for Coupled Superconducting Resonators”
American Physical Society March Meeting, (March 21, 2011)

David Tucker-Smith

“An Effective Z”
University of Maryland particle theory seminar, April 2011
Boston University particle theory seminar, May 2011
UC Berkeley particle theory seminar, May 2011
SLAC particle theory seminar, May 2011

Bill Wootters

“Introduction to Mutually Unbiased Bases” and “States that Look the Same in Each Basis of a Complete Unbiased Set”
Workshop on Quantum Theory in Higher Dimensions, Traunkirchen, Austria, July 2010

“Doing Physics with Undergraduates in Williamstown and Kigali”
meeting of the Anacapa Society, Pomona, CA, December 2010

“Isotropic States in Discrete Phase Space”
APS March meeting, Dallas, TX, March 2011