Physics and Astronomy Cover: Close-Up Photo of Single Crystals of Geometrically Frustrated Antiferromagnets, Such As Strontium Holmium Oxide

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Johns Hopkins University 2011 Physics and Astronomy Cover: Close-up photo of single crystals of geometrically frustrated antiferromagnets, such as strontium holmium oxide. The crystals pictured here were grown in the crystal-growth facility of the Department of Physics and Astronomy’s Institute for Quantum Matter by research scientist Seyed Koohpayeh. Conflicting magnetic interactions in these materials pro- duce a rich variety of emergent phenomena, including the exotic spin-liquid state of matter.

This page: The crystals at approximately 2.5 times their actual size. See related article on page 6.

TABLE OF CONTENTS Letter from the Chair 1 Chasing the Origins of the Universe 2 Discovery on a Grand Scale 4 A New Spin on Quantum Matter 6 Research Briefs 8 People 11

Physics and Astronomy is an annual publication of the Johns Hopkins University Zanvyl Krieger School of Arts and Sciences Department of Physics and Astronomy. Send correspondence to: Kate Pipkin, 3400 N. Charles Street, Wyman 500W, Baltimore, MD 21218 or [email protected].

Editor Kate Pipkin

Managing Editor Ian Mathias

Design Johns Hopkins Creative Services

Photographer Will Kirk, Homewood Photography (unless otherwise noted) Letter from the Chair

Dear alumni, colleagues, and friends, ctober 4 was a banner day for Johns Hopkins and especially for our Depart- ment of Physics and Astronomy. That was the day Adam Riess, who holds a OKrieger-Eisenhower Professorship in our department, was named a Nobel Prize winner for his leadership in the High-z Team’s 1998 co-discovery that the expansion rate of the universe is accelerating, a phenomenon widely attributed to an unexplained “dark energy” filling the universe. This level of achievement on the part of one of our faculty members is an affirmation of the intense quest for knowledge that is under way in our department every day. I believe that every physics and astronomy graduate has played some part in advancing the scholarship of this field. Each of you has a connection—be it past or present—to our department, and I know you share our pride in Adam’s great accomplishment. Even as we take time to celebrate this achievement (and celebrate we did!), the Department of Physics and Astronomy continues to move forward—sowing the seeds for the next round of discoveries in our disciplines. The department has recently embarked on a variety of new ventures, from a partnership with the National Laboratory of Solid State Microstructures at Nanjing University, to forefront work at the Large Hadron Collider at CERN, to building a state-of-the-art telescope in the Atacama Desert in Chile, and to numerous projects on the Homewood campus here in Baltimore. No matter where they work, our diverse faculty and students share a commitment to deepening our understanding of the most basic, irreducible foundations of nature. I am fortunate to keep the company of so many scholars dedicated to forging new frontiers for our discipline. In a similar vein, you hold in your hands another new venture for the department: an annual publication. Though it contains just a sampling of the work we have conducted over the past year, it will inform you of some of the department’s endeavors, and I hope it inspires you to remain in contact. Enjoy this inaugural issue.

Best,

Daniel Reich, Chair The Henry A. Rowland Department of Physics and Astronomy

JOHNS HOPKINS UNIVERSITY PHYSICS AND ASTRONOMY 2011 1

PHA report_fin.indd 1 1/10/12 3:12 PM Chasing the Origins of the Universe…

With a $5 million grant from the investigator for the 2001 Wilkinson Micro- Right down to the first trillionth National Science Foundation, Bennett is wave Anisotropy Probe space mission, which “One of the most leading a team developing a ground-based improved cosmic parameters by a factor of of a trillionth of a second telescope to study the origin of the universe. 30,000, fixing the age of the universe to rewarding things is strophysicist Charles “Chuck” The instrument will probe the cosmic within 1 percent accuracy.) BennettA has spent more than 25 years microwave background radiation—faint The instrument will work somewhat studying faint afterglow radiation from the traces of the universe’s very beginning, 13.7 like a satellite television dish. A reflector and seeing undergraduate earliest moments of the universe. billion years ago. circuitry within the instrument will intercept Bennett, the Alumni Centennial Called the Cosmology Large-Angular microwaves coming from space and direct and graduate students Professor of Physics and Astronomy who By Karen Blum Scale Surveyor (CLASS), the telescope will the signal onto an array of tiny devices came to Johns Hopkins in 2005 from the search large regions of the sky for a specific (superconducting transition edge sensors or National Aeronautics and Space Administra- polarization pattern generated by gravita- bolometers), where that energy will be really dig into the tion (NASA), says there are many unan- tional waves formed during the first absorbed. The device heats up slightly due to swered questions about the universe. His is, moments of the universe. Bennett hopes it this absorbed energy, allowing the team to project. It’s a great “What happened at the very beginning?” will help provide a definitive test of the record the energy coming from different “You might think that this is not theory of inflation, which suggests that tiny directions of the sky. For this to be possible, answerable by humans,” he says, “and it may quantum mechanical energy fluctuations the team has to cool the detectors within the combination of not be, but we’re going to try.” suddenly grew at an enormous rate to an instrument to a tenth of a degree above astronomical size to start the universe. absolute zero. A position-cycled grid of wires enthusiasm and “This inflation theory, in my mind, is located in front of the instrument will rapidly like a theory that adds on to the beginning modulate the polarization state input to the of the Big Bang theory,” he says. “Inflation detectors so the instrument’s effects can be transfer of expertise.” theory actually is the theory of how things separated from sky polarization. got started.” While most cosmologists agree CLASS will be built at Johns Hopkins —M Tobias arriage, that the universe started very hot and dense and transported to the Atacama Desert of Assistant Professor and has been expanding and cooling ever northern Chile—one of the highest, driest since, the Big Bang theory many use to places on earth. Bennett has been working explain the universe’s origin has become with the Chilean government for permission misconstrued, Bennett says. According to to situate the instrument 17,000 feet above Princeton he worked on the Atacama him, the Big Bang theory clarifies how the sea level in an evolving astronomical park Cosmology Telescope (ACT), located on the universe has evolved, but it doesn’t tell us scattered with other telescopes and observa- same Chilean plateau where CLASS will how it began. tories. Last year, he visited the area to select a reside. Marriage studies clusters of galaxies Looking at the cosmic microwave specific location for the telescope, in view of that were found by their effect on the cosmic background is looking straight into the past, the town of San Pedro de Atacama, some microwave background, and uses this due to the finite speed of light, Bennett 9,000 feet below. Because the desert’s information to deduce additional properties explains. “We are directly looking at what the extreme temperatures and little oxygen make of the universe. universe looked like 13.7 billion years ago. It for an inhospitable work environment, he Marriage has been working closely isn’t an idea, or a concept, we are looking at plans to have an antenna transmit the data with Johns Hopkins physics and astronomy the light from 13.7 billion years ago, and from the telescope to town so team members students designing state-of-the-art technol- that’s what’s so cool about it…it’s incredibly can access the information on computers at a ogy for CLASS, including the optical exciting to try to use this data to figure out more moderate altitude, limiting the amount instrumentation and a shield to protect the what happened in the first trillionth of a of time spent on-site each day. detectors from the Earth’s magnetic field. trillionth of a second of the universe.” (It’s Now a year into the five-year grant, the “One of the most rewarding things is worth noting that Bennett was the principal team is well on its way to constructing the seeing undergraduate and graduate students telescope. A lab (pictured left) across from really dig into the project,” Marriage says. Bennett’s office houses part of the instru- “It’s a great combination of enthusiasm and Facing page: Several members of the CLASS team. ment’s core circuitry, as well as cryogenic transfer of expertise. From left: Assistant Professor Tobias Marriage, cooling equipment. An adjacent room holds “This is a real watershed moment,” Graduate Research Assistant Joseph Eimer, their polarization filter, consisting of hun- he adds. “This project hopefully will be the Professor Charles Bennett, and Undergraduate dreds of thin gold wires, stretched taut. gateway to many, many more cosmological Research Assistant Tiffany Wei. Between Eimer A key member of the team is Assistant experiments over the next decades.” If and Bennett rests a helium refrigerator system Professor Tobias Marriage, who came to CLASS detects the anticipated signal, it and dewar, which are used in conjunction to cool Johns Hopkins last year from Princeton would be the first-ever detection of the CLASS detectors to 100 millikelvin—just one-tenth University. Marriage has also been studying gravitational waves that signify the origin the cosmic microwave background, and at of the universe. of a degree above absolute zero.

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PHA report_fin.indd 3 1/10/12 3:12 PM “A huge mystery is why the top quark weighs 175 times the mass of a proton—about as much as an atom of gold.”

– Jonathan bAGGER, Professor

Blumenfeld, Andrei Gritsan, Petar Maksi- The work has been challenging. Particle physicists worldwide are now movic, Morris Swartz, and their postdocs Useful collision-product-detection requires scrutinizing data from LHC detectors for and students—helped assemble one of hardware and software that is sensitive statistical hints of the Higgs—which theo- LHC’s two main detectors, the Compact enough to distinguish the fleeting tracks of retically was unlikely to manifest itself at the Muon Solenoid (CMS). The 14,000-ton infinitesimally spaced subatomic particles; Tevatron. Gritsan, who has worked to install device enables physicists to detect and sophisticated enough to flag the noteworthy and align key CMS detectors, designed analyze the collision-products that explode events amid the billions of proton-proton special software to pick up decay products outward from these proton-on-proton collisions that take place in a typical day of that could occur if the Higgs emerges briefly impacts. operation; and robust enough to stay useful into existence. “If you were to create a Higgs “We took our experience working even after months and years within a mael- boson, it would live so briefly that the only with detectors at the Tevatron and brought strom of radiation. “To continue to get value way to see it would be to detect the channels that to the CMS,” says Barnett. “We col- out of the detectors as they’re being degraded of products from the two photons, or two W laborated with other institutions to design by radiation is tricky,” says Jonathan Bagger, bosons, or two Z bosons into which it can the silicon detectors inside the CMS, care- a Krieger-Eisenhower Professor and theoreti- disintegrate,” he says. fully assembled them, tested them, shipped cal physicist at Johns Hopkins. By early August, data from the LHC them off to CERN, and played a part in the But now the CMS detectors are in had ruled out the existence of a Higgs-like delicate process of installing them.” place and yielding vast amounts of data— particle over much of its allowed mass range. “We’ve also developed some advanced with which physicists hope to soon discern By the end of 2012, says Gritsan, Hopkins software for these detectors, and have been the answers to some important questions. researchers expect the Standard Model Higgs designing some next-generation tracking Atop their list is the question of whether the boson to be either observed or completely instruments,” says Swartz, the principal in- hypothetical Higgs boson exists. Discovery ruled in. While finding the Higgs would vestigator for the NSF grant that funds most of the Higgs boson would explain why the shore up the Standard Model, not finding it of Johns Hopkins’ research at the LHC. W and Z bosons—which mediate the weak wouldn’t be considered a failure: “If we don’t find it, we’ll probably find something else Installation of the CMS silicon tracking detector that Johns Hopkins researchers helped design, test, and install. (Photo courtesy of CERN) that will be even more interesting and exciting,” Gritsan says. There are other, less popularly discussed puzzles that the LHC could help solve. One of these puzzles has to do with the Discovery on a Grand Scale top quark, discovered at Tevatron in 1994. “A huge mystery is why the top quark weighs 175 times the mass of a proton— about as much as an atom of gold,” says Bagger. “Since top quarks have so much mass, they must be intimately involved with Hopkins physicists play undreds of feet beneath the tium CERN, with some U.S. funding and whatever gives quarks and leptons their countrysideH west of Geneva, Switzerland, the plenty of U.S. participation, the LHC has important role with mass; what you really want to do is to study Large Hadron Collider (LHC) has captured been moving into normal working mode Large Hadron Collider them every way you can.” the attention of particle physicists world- over the past few months. More than 6,000 Johns Hopkins professors (theorist wide. The 17-mile circular synchrotron is particle physicists around the world are now David Kaplan and experimentalist Maksi- the newest and largest particle-collider on trying to map its huge flow of data onto movic) have been busy determining how top By Jim Schnabel the planet—capable of boosting clusters of the Standard Model of particles and forces, quarks should appear in LHC collisions and protons to 99.9999991 percent of the speed which has held up well until now, but still integrating their techniques into CMS detec- of light, and steering them against protons contains terra incognita that only multi-TeV tor software algorithms. that come at the same speed from the oppo- energies can illuminate. JHU physicists are also hoping the site direction. Its proton-on-proton collision “You can think about it as almost like LHC might help solve some of the questions energies reach 7 TeV, and are expected to a voyage to discover the Americas,” says As- surrounding dark matter, whose existence attain energies as high as 14 TeV by 2014, sociate Professor Kirill Melnikov. “We’re still An event with the production of four muons nuclear force—have mass, while the pho- astronomers infer from their observation seven times higher than the collision energies in the middle of the journey; we don’t know in the proton-proton collisions at the LHC, ton—which mediates the electromagnetic that the visible matter in the universe cannot achieved at Fermilab’s Tevatron in Batavia, that we’re going to discover anything, but if observed in the CMS detector. Such events are force—does not. account for all of the universe’s gravity. “If Illinois—the world’s largest collider before we do, it will be a discovery on a grand scale.” important in the search for the Higgs boson, “The Higgs mechanism is the simplest dark matter reacts even weakly to the usual the LHC. Johns Hopkins has been a part of this as the production of four muons is a potential hypothetical mechanism that would give collision-measuring instruments, then there’s “The LHC is essentially a machine for journey from its beginning. Even before the decay mode of the Higgs. (Courtesy of CERN) masses to these particles without breaking a reasonable chance that it can be detected at detecting new physics,” says Department of LHC’s construction was completed in 2008, the Standard Model,” says Melnikov. “But LHC,” says Melnikov. “Should that hap- Physics and Astronomy Professor Bruce Barnett. Johns Hopkins experimental particle being the simplest proposed mechanism pen, it would be a totally different game for Run by the European physics consor- physicists—Professors Bruce Barnett, Barry doesn’t mean that it is the correct one.” physics.”

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PHA report_fin.indd 5 1/10/12 3:12 PM A New Spin on Quantum Matter

Broholm and his colleagues can infer the By Jim Schnabel Denmark, Broholm leads a team of scientists Physics and Astronomy with similar interests and complementary amount of energy and momentum delivered Professor Collin Broholm expertise in the Johns Hopkins-Princeton to spinons—and thus infer properties of the spinons themselves. With 50 times the explores the unusual Institute for Quantum Matter (IQM). Johns ollin Broholm, the Gerhard H. Hopkins professors Zlatko Tesanovic and number of neutrons per time unit hitting the spin-liquid state. DiekeC Professor of Physics and Astronomy, Oleg Tchernyshyov focus on the theory sample and 20 detectors to collect scattered is on the trail of a new and exotic state of of quantum-correlated materials; Tyrel neutrons, MACS is much more efficient than matter known as a “spin-liquid” state. McQueen and Robert Cava of the Johns conventional instrumentation and is provid- “Our motivation is almost entirely Hopkins and Princeton departments of ing a whole new view of magnetism and to learn new, fundamental physics, but we chemistry, respectively, synthesize spin- electronic correlations at the atomic scale. also have an eye out for applications,” says liquid-prone materials; and Broholm and Broholm and his colleagues say they Broholm. “In condensed-matter physics Hopkins physicist N. Peter Armitage probe are also excited about the capabilities of the there can be a beautiful confluence of basic the collective properties of new materials. completely new Spallation Neutron Source phenomena and practical application.” In Specifically, they use neutrons or photons to (SNS) at the Department of Energy’s facility the case of spin-liquids, the exotic quasi- detect novel quasi-particles and determine in Oak Ridge, Tennessee (Broholm has a particles they host could one day become the whether the new materials match the theory. joint-faculty appointment there). The SNS Q-bits of a super-fast quantum computer. Some of this work requires large produces neutrons by “spallation” of nuclei The spin-liquid state is closely related to the superfluid state of helium near the ab- “THE Spallation Neutron Source is on a solute zero temperature, because like in liquid helium, quantum fluctuations preclude different scale. The neutron-detecting a periodic ordered state. “A material in the spin-liquid state is one that should be mag- systems on the output side are the size netically ordered from a classical viewpoint but remains a fluid,” says Broholm. “It’s the of houses.” — Collin Broholm, professor magnetic equivalent of superfluid4 He.” Like superfluid4 He, which has unique roton excitations, electrons in spin-liquids and expensive equipment that universities when energetic protons from a ~1 GeV can fractionalize into spinons and holons– cannot afford to operate, so Broholm uses accelerator strike a dense target. The pulsed quasi-particles that separately carry the facilities run by the federal government. The incident proton beam creates a pulsed electrons’ spin and charge. Broholm and National Institute of Standards and Technol- neutron beam with peak intensities much his colleagues are on a quest to expose new ogy (NIST) Center for Neutron Research is greater than is possible at a reactor-based forms of collective quasi-particles within conveniently located in Gaithersburg, Md, facility. “SNS is on a different scale,” says crystalline solids to understand their interac- and Broholm was the principal investigator Broholm. “The neutron-detecting systems on tions, impact on materials properties, and for a novel instrument that has just been the output side are the size of houses.” He potential for technical applications. completed there. The Multi-Axis Crystal should know, having served as the chair of A quantum computer would replace Spectrometer (MACS) was jointly funded by the SNS’s Experimental Facilities Advisory the usual binary 1-or-0 bits by the magnetic NIST, the National Science Foundation, and Committee from 2002 to 2006. For his states of so-called qubits, which exist in an Johns Hopkins, and 20 percent of the beam scientific research and his work to develop unresolved, maybe-1-maybe-0 state during time on it is available for IQM research. neutron scattering instrumentation, the calculations. As a result, a continuum of cal- By probing the distribution of neutrons Neutron Scattering Society of America culations is conducted, from which the result scattered from the materials of interest, (NSSA) awarded him its 2010 Sustained of interest can be projected upon completion. MACS provides an atomic scale view of Research Prize. For certain types of computation, this makes structure and motion in materials. “Neutrons Broholm’s work on the spin-liquid a qubit-driven computer dramatically faster are perfect for what we’re trying to do,” says state most recently led him to Japan, where than an ordinary binary computer. The chal- Broholm. “They don’t have charge, so they he spent several months visiting with physi- lenge is to realize a qubit that operates coher- enter materials without disturbing things too cists at the University of Tokyo’s Institute for ently long enough to complete a calculation. much. Yet they do carry a magnetic dipole Solid State Physics. “Over the last 20 years or “A spin-liquid might do the job because the moment and can deliver energy and momen- so, they’ve developed a lot of expertise in the collective nature of spinons can protect them tum to spinons through quantum collisions, discovery and characterization of novel elec- from defects and noise,” says Broholm. witnessed by the pattern of neutron tronic materials, so I’ve been visiting there to Originally from Copenhagen, scattering.” strengthen our collaboration,” he says. “They By knowing the energy and momen- bring expertise in materials production, and tum of neutrons as they enter a material on our side we’re helping to disentangle Facing page: Collin Broholm, the Gerhard H. Dieke and measuring how much these changed in atomic scale properties of strange quantum Professor of Physics and Astronomy the course of interacting with the material, magnets through neutron scattering.”

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PHA report_fin.indd 7 1/10/12 3:12 PM RESEARCH BRIEFS u. arrea C

. C

A explains McCandliss. “Programs such as this S Hopkins Astrophysicist E further the Hopkins tradition of creating new

y of of y Awarded $3.2 Million NASA s science with innovative instruments, while Grant to Build Sounding Rocket providing unique opportunities for hands-on Stephan McCandliss, an astrophysicist at training of students.” Johns Hopkins since 1988, has been awarded Photo courte Photo a $3.2 million grant from NASA to build and launch a sounding rocket-borne spectro-tele- Grant Funds Collaboration with scope called FORTIS, which could ultimately Nanjing University and Chinese Physics and Astronomy define the origins of the meta-galactic ion- Professor Rosemary Wyse izing background that permeates space. The National Laboratory grant is a continuation of a 2004 NASA grant The Department of Physics and Astronomy called “Rocket and Laboratory Experiments in was among the first wave of departments to Astronomy—FORTIS: Pathfinder to theL yman receive funding from the new JHU Benjamin Continuum.” and Rhea Yeung Center for Collaborative According to McCandliss, the China Studies. The center chose 11 proposals 1,123-pound, 24-foot-long rocket payload, to fund this year, its first year of operation, in- The Matter of the Universe scheduled to be launched in early 2012 from cluding one from the physics and astronomy New Mexico, will be used to measure the department that would forge a partnership s a founding member of the RAVE (Radial Describing this part of her work as escape of Lyman alpha (the principal spectral A with the National Laboratory of Solid State Velocity Experiment) collaboration, Physics “galactic archaeology,” Wyse has focused line emitted by atomic hydrogen) from Microstructures (NLSSM) at Nanjing Univer- and Astronomy Professor Rosemary Wyse much of her research on the stars in the Milky nearby star-forming galaxies. sity. The department will receive $150,000 per studies the motions and chemical composi- Way galaxy, the object of the RAVE effort. “ McCandliss, with the assistance of a year to work with the laboratory, initially on tions of 36,561 stars in the Milky Way galaxy. The stars in our galaxy cover the whole history Data from Herschel Observatory Unlocks Clues to Star Formation small crew of graduate students and engi- joint research in condensed matter physics. Data acquisition from this international of the universe, from the oldest stars to the Physics and Astronomy Professor David Neufeld has been gathering and analyzing data from the neers, has constructed much of the sound- It is expected that the Yeung Center will fund project is slated to conclude in 2012, after youngest,” she says, making it a perfect mix Herschel Space Observatory (pictured above), the largest infrared observatory in orbit. Herschel’s ing rocket from scratch, within the labs and this project for up to five years. The project’s nine years of observation, and Wyse hopes of star evolution to observe. One of Wyse’s 3.5 meter diameter reflecting telescope (the largest single mirror ever built for a space telescope) offices of the BloombergC enter for Physics principal investigators, Professor Chia-Ling that the subsequent final analyses will reveal pivotal research achievements was in and its Heterodyne Instrument for the Far Infrared (HIFI) allow the observatory to measure and Astronomy. Using this multi-object Chien from Johns Hopkins and Professor Mu new theories on how galaxies are formed and characterizing the stellar population of the frequencies to one part in a million, “which makes it particularly good at observing molecules in spectro-telescope, enabled by micro shut- Wang, the director of the NLSSM at Nanjing the nature of dark matter. thick disk in the Milky Way and to point out space,” explains Neufeld. He has been using Herschel’s exceptional power to discover and analyze ters that control the selection of light, he has University, have planned several modes of re- “We want to infer, from looking at the its importance in constraining or defining previously undetectable clouds of interstellar gases, most notably those that contain water or devised innovative ways to observe galaxies, search, focused on current research problems stars now, what conditions were like when the dark matter. hydrogen fluoride. Both gases are commonly present at the beginning and at the end of a star’s estimate their origins, and ultimately answer of mutual interest and involving interactions they formed,” says Wyse. Although there have In all of Wyse’s research, dark matter life cycle, and Neufeld’s work may ultimately become essential in tracing star formations in more the question, “How did the universe come to and reciprocal exchanges by faculty, post- been other similar spectroscopic surveys in plays a critical role. “The merger history of the distant galaxies. be ionized?” Continued on p. 10 addition to RAVE, “each has its own niche in Milky Way is driven by this mysterious dark “This is really entrepreneurial science,” the sense of what piece of the galaxy you’re matter. If we can figure out the merging looking at and what sort of spectra you’re history—and therefore galaxy evolution— New Course Combines Space Science and Engineering getting.” then we can place constraints on the nature The department has launched a new course C amera for the Chandra X-ray Observatory; According to Wyse, the RAVE survey, of dark matter.” — Diana Schulin called Introduction to Space Science and and John Grunsfeld, an astronaut on five funded by the National Science Foundation, is Technology, designed for undergraduate stu- NASA space flight missions. unique in that it is looking at all types of stars, dents preparing for a career in space science “This course has a somewhat hidden and encompasses a large enough sample to and engineering. The course addresses topics agenda as well,” says Moos. “Students are discover unusual objects to study. such as conducting research in the space going to begin to understand how to design, “It’s exciting,” says Wyse, “because environment, space mission design, systems implement, and accomplish very large scien- we have a lot of new data right now, and at engineering, and human operations in space. tific enterprises.T hat skill set will be useful, no the same time we’re beginning to have the Last semester the course was team-taught by matter what they do after Hopkins.” Building computer power to do the matching detailed three faculty members with extensive experi- on this cross-disciplinary approach, Space simulations of galaxy formation—so we can compare them with the great observations ence on the subject: Warren Moos, principal Science and Technology is co-listed by the Research Professor Stephan McCandliss (left) investigator for the Far Ultraviolet Spec- physics and astronomy; earth and planetary oversees graduate students Keith Redwine (center) From left: Professor Hai-Hu Wen, of Nanjing Univer- that we’re getting.” troscopic Explorer (FUSE); Stephan Murray, sciences; materials science and engineering; and Brian Fleming as they assemble the FORTIS sity, and Johns Hopkins professors Chia-Ling Chien principal investigator for the High Resolution and mechanical engineering departments. payload in preparation for a focus test. and Tyrel McQueen.

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PHA report_fin.indd 8-9 1/10/12 3:12 PM PEOPLE

Grant Funds from p. 9 docs, and graduate students. A group of who have demonstrated great potential Johns Hopkins faculty traveled to Nanjing in for future scientific accomplishment.” T he F our New Named Professorships Awarded August to kick off the program. “This looks Department of Physics and Astronomy like a highly promising partnership,” says lauded his work as well, awarding Shen the The Department of Physics and Astronomy Adam Riess, the Krieger-Eisenhower awards and honors, he most recently Department Chair Daniel Reich, who was part 2011 Donald E. Kerr Memorial Award, given honored four faculty members with named Professor in Physics and Astronomy (and received the 2011 Balzan Prize for his of the delegation. “We were able to establish annually to an outstanding physics major. professorships in 2011. Timothy Heckman recent Nobel Prize recipient—see back inspired work on the early universe. His links and connections with faculty at Nanjing Shen shared the honor with Justin Silverman was named the inaugural Dr. A. Hermann cover), has played a critical role in discover- professorship, named in honor of the University in this first visit that we will be able and Xinlu Huang. Pfund Professor in early May, while Charles ing the nature of dark energy. In addition School of Arts and Sciences’ north Baltimore to build on in the coming years.” This initia- Now a graduate student at MIT, Shen Bennett, Adam Riess, and Joseph Silk to his named professorship, Riess has campus, was established by the school’s tive will likely lay the groundwork for future continues to work with the Tchernyshyov were granted named professorships in garnered many other honors, such as the Academic Council. late September in a celebration of their Sackler Prize, the Shaw Prize in Astronomy, Johns Hopkins–Nanjing partnerships within group, whose members are preparing a full- “Appointment to an endowed chair accomplishments. the Gruber Prize in Cosmology, a MacArthur has been a coveted honor for distinguished the department and in other physical science length article on their research for the New Fellowship, and the Einstein Medal. The faculty ever since the first professorships disciplines, such as materials research. Just as Journal of Physics, in which Shen will be the Timothy Heckman, the inaugural Dr. A. Krieger-Eisenhower Professorship is a were created five centuries ago at the important, the new affiliation offers students lead author. Hermann Pfund Professor, has played a tribute to one of the university’s greatest universities of Oxford and Cambridge,” Dean and faculty not only a chance to collaborate major role in defining the understanding of benefactors, Zanvyl Krieger, and his close Katherine Newman noted at the September with their peers in Nanjing, but also a tremen- black holes and star formation. Aside from friendship with former Johns Hopkins event that celebrated Bennett, Riess, and dous opportunity to broaden their social and 2011 Gardner Fellow Works 2011 Gardner Fellow Danru Qu his numerous awards and achievements, University President Milton Eisenhower. Silk. “Those who hold endowed chairs are cultural horizons. Heckman is also the director of the Johns leaders in their fields. T hey are the pioneers at Crossroads of Biology and recently invented electric tweezers, which can Hopkins Center for Astrophysical Sciences, Joseph Silk, the Homewood Professor in who will chart new courses of discovery and Condensed Matter Physics rotate minuscule objects, including bacteria. which is a focal point for the activities of Physics and Astronomy and one of the attract the brightest and most promising Since rotation characteristics depend on the the more than 100 astrophysicists in the Undergraduate Publishes department’s most recent hires, has students. These faculty members bring Danru Qu has been named the 2011 William geometrical details of the object, bacteria department. His professorship is named in established himself as one of the world’s added luster to the name of Johns Hopkins.” Research on Spin Ice; Gardner Fellow. This award, given to first- or with different flagella would display different honor of Dr. A. Hermann Pfund, who in many leading theoretical astrophysicists over his Garners Awards second-year physics and astronomy graduate rotation characteristics. “It could be possible ways set the foundation for modern astrono- 40-year career, having published more than students, relieves promising young scholars to differentiate bacteria in liquid by their my during his tenure at Johns Hopkins from 500 scholarly papers. Among his many Physics major Yichen Shen ’11 was recognized like Qu of their teaching duties for one semes- response to an external electric field,” says Qu. 1903 to 1947. this year for his impressive study of artificial ter so they can get a head start on doctoral “In this manner, we can identify bacterial spin ice, a class of nanostructured materials research. species without actually ‘seeing’ the flagella.” harboring magnetic monopoles. In his junior Qu, now a second-year graduate Such an achievement “would be a year, Shen started working under the supervi- student, has already demonstrated a talent scientific first,” saysC hia-Ling Chien, the Jacob sion of Oleg Tchernyshyov, a professor and and zeal for her area of interest—using the L. Hain Professor of Physics and one of Qu’s condensed matter theorist in the department, tools and principles of condensed matter mentors in the department. “I am impressed on a research project funded by a Hopkins physics to attempt to differentiate species of by Danru’s academic record, drive, and deter- Provost Undergraduate Research Award. Shen bacteria. “Various species of bacteria have dif- mination.” utilized his analytical training (he received ferent numbers and arrangements of flagella,” Qu is the third Gardner Fellow. The fel- Professor Timothy Heckman a BS in physics and an MA in mathematics she explained in her fellowship proposal. lowship was founded by William Gardner ’68, during his four years at Johns Hopkins) to con- “Despite their importance in the mobility of who received his PhD in physics under Professor Charles Bennett, the Alumni Centennial duct numerical simulations of the Tchernyshy- bacteria, flagella are hollow tubes only 20 nm Warren Moos. After a successful career in fiber Professor in Physics and Astronomy, is one of the world’s leaders in the study of the ov group’s research, uncovering a deficiency in diameter, too small to be seen by optical optics and telecommunications, Gardner now cosmic microwave background radiation. in their original model and helping the group microscopy.” supports a high priority of the department— Bennett has garnered many awards and build a reliable description of the system Thus, Qu will use the research time enabling graduate students to start their accolades for his research, including doctoral research as early as possible. that agrees with experiments. He went on to afforded by the fellowship to experiment with election to the National Academy of analytically derive a statistical distribution of Sciences, the Henry Draper Medal, the magnetic avalanches and perform numerical Gruber Prize in Cosmology, the Harvey simulations that confirmed his predictions. Prize, the Comstock Prize in Physics, and the Shen’s research was published this “It could be possible to differentiate bacteria in Shaw Prize in Astronomy. His professorship year in a co-authored article in Physical liquid by their response to an external electric was named in honor of the alumni on the occasion of the university’s 100th birthday, Review Letters. His work on artificial spin ice field. In this manner, we can identify bacterial also caught the attention of the American celebrated in 1976 with a year of events Physical Society, which named him a finalist species without actually ‘seeing’ the flagella.” and a symposium that brought scholars from all over the world to Johns Hopkins. in their annual LeRoy Apker Award, a distinc- —Danru Qu From left: Department Chair Daniel Reich, School of Arts and Sciences Dean Katherine Newman, and tion the society awards to “young physicists Professors Adam Riess, Charles Bennett, and Joseph Silk.

10 JOHNS HOPKINS UNIVERSITY PHYSICS AND ASTRONOMY 2011 JOHNS HOPKINS UNIVERSITY PHYSICS AND ASTRONOMY 2011 11

PHA report_fin.indd 10-11 1/10/12 3:12 PM New Appointments me to design and synthesize new materials Johns Hopkins Receives Grant containing electrons displaying emergent to Upgrade Maryland’s Internet Marc Kamionkowski joined the depart- behaviors,” he says. “But my lab’s location— ment in the 2011–12 academic year in the Department of Physics and Astrono- Pipeline after serving as an endowed professor of my—encourages me to explore the physical theoretical physics and astrophysics at the properties of the materials I’m researching Johns Hopkins University and the California Institute of Technology. Kami- on a level usually studied by condensed University of Maryland at College Park re- onkowski, who earned his PhD in physics matter physicists.” ceived a $1.2 million grant from the National from the University of Chicago, is a world Science Foundation (NSF) to build one of the leader in the study of dynamics, large scale Brice Ménard joined the Department of world’s fastest and most advanced scientific structure, and early Physics and Astronomy in 2010–11, after networks. history of the universe. working as a senior research associate at the “This bandwidth upgrade will allow His current research Canadian Institute for Theoretical Astro- enormous scientific data sets to be moved interests include dark physics. An assistant professor, Ménard is a to Johns Hopkins from Google, the Oak matter, inflation and theorist who is interested in extragalactic Ridge National Laboratory, and the San the cosmic microwave astrophysics and cosmology. background, and Diego Supercomputer Center, for example,” By mining large data sets to gain in- cosmic acceleration. said Alexander Szalay, Alumni Centennial sight into the universe, he has made major Professor of Physics and lead researcher on discoveries about the relationship between the grant. stars, dark matter, and the presence of The department welcomed Tobias The network, supported by NSF’s Marriage in 2010–11 as an assistant profes- tiny grains of dust around galaxies. Mé- Office of Cyberinfrastructure, will be one of sor after postdoctoral study at Princeton nard earned his PhD the country’s first public 100 GbpsI nternet University. Marriage is an experimental from the Max Planck connectivities, allowing Johns Hopkins and cosmologist who is playing a leading role in Institute for Astrophys- experiments to observe the cosmic micro- ics and concluded its collaborators to stay on the cutting edge wave background and answer important postdoctoral research of science, moving data sets thousands questions about the origins and evolution at the Institute for of times bigger than previously possible. of the early universe and the nature of Advanced Study in The network will be built at Johns Hopkins dark energy. His research activities include Princeton, N.J. University at the Bloomberg Center for millimeter-wave instrumentation, fieldwork, Physics and Astronomy and supported by and analysis. Current projects include the Nadia L. Zakamska is a theorist and the regional MAX research and engineering Atacama Cosmology observational astronomer who joined the network aggregation point at the University Telescope, the Ata- department in 2010–11 as an assistant of Maryland. cama B-mode Search, professor. She was previously a research and the Cosmology associate at the Kavli Institute for Particle Large Angular Scale Astrophysics and Cosmology at Stanford Surveyor. He earned University. Before that, she was a five-year his PhD from Princeton member at the Institute for Advanced Study. in 2006. Zakamska, who earned her PhD in astrophysics from Princeton University, focuses After completing graduate studies at her research on observational astronomy, Princeton and a postdoc at MIT, Tyrel including active galactic nuclei and ultra- McQueen came to Johns Hopkins in luminous infrared 2010–11 as an assistant professor in the galaxies, and theoreti- physics and astronomy department and cal astrophysics, the chemistry department. McQueen’s including outflows study of materials from compact objects straddles the line and dynamics of stellar between inorganic and planetary systems. chemistry and condensed matter physics. Professor Alexander Szalay “My primary appointment in the chemistry department allows

12 JOHNS HOPKINS UNIVERSITY PHYSICS AND ASTRONOMY 2011

PHA report_fin.indd 12 1/10/12 3:12 PM Not Your Average Server Room A former mission control center has been transformed into the new home for Johns Hopkins data-intensive computing.

There’s a large—3,100 square feet—brightly lit room on the the new data center: first floor of the Bloomberg Center that was once a critical • Two towers of graphics processing unit (GPU) powered base for the Far Ultraviolet Spectroscopic Explorer (FUSE). It computers called the 100Teraflop Graphics Processor was the control center for the FUSE, which was launched into Laboratory. One teraflop denotes the ability to perform one space in 1999 and operated until late 2007. Four years later, trillion operations per second. the room is now repurposed, dedicated to exploring a realm • 10 gigabyte-per-second connectivity between clusters in that is quickly becoming nearly as vast and difficult to navi- the data center and computers elsewhere on the Johns gate as space itself: data. Hopkins network. Funded in part by the National Science Foundation • Over 3,500 compute cores in the HHPC (each comparable to through an American Recovery and Reinvestment Grant, the those in a fast desktop PC) that can be harnessed to work in new data center serves both the Krieger School of Arts and parallel on complex problems. Sciences and the Whiting School of Engineering, and several • A direct connection to Internet2—an advanced networking major computing clusters in the room are dedicated to consortium of academic and research clusters like the HHPC projects led by physics and astronomy faculty members. By from around the U.S. More than 350 member institutions the end of 2011, the data center will house two data-intensive will soon share 100 gigabit-per-second connectivity and 8.8 computing clusters, dubbed GrayWulf and Data-Scope; the terabits of capacity, granting research institutions like Johns entire Homewood High-Performance Cluster (HHPC), and Hopkins unprecedented shared-computing capability. several other state-of-the-art computing projects. Each will be used to create, store, organize, and eventually interpret • GrayWulf, the largest database in any university, has roughly the vast amount of data generated from disciplines such as 1.5 petabyte storage capacity. That’s equivalent to 6,000 astrophysics, genetics, condensed matter physics, environ- 250 gigabyte hard drives—a typical amount of storage on a mental science, or bioinformatics. consumer laptop. When completed, Data-Scope will have a Only partially completed as of this fall, here is a 10 petabyte capacity. sampling of the computing power already available in Zanvyl Krieger School of Arts and Sciences 500 W Wyman 3400 North Charles Street Baltimore, MD 21218

Congratulations, Adam Riess!

Adam Riess (left) celebrates his Nobel Prize with Department Chair Daniel Reich (right).

n October 4, 2011, Adam Riess, the Krieger-Eisenhower The Nobel committee was careful to award the prize for the discovery OProfessor of Physics and Astronomy, became Johns Hopkins of the acceleration, leaving aside the vexing question of what is causing University’s 35th Nobel laureate. The Royal Swedish Academy of the expansion to accelerate. Theories abound under the catch-all phrase Sciences’ early morning announcement hailed Riess’ discovery of the “dark energy,” including Einstein’s cosmological constant, vacuum universe’s accelerating expansion as one of the most profound and energy, an evolving universal scalar field or fields, or a flaw in the theory important of our generation. of general relativity. Whatever the cause, the discovery is a landmark that Riess shares the prize with Brian Schmidt, of the Australian will change cosmology, and possibly fundamental physics. National University, who worked directly with Riess; and Saul “We at the Krieger School of Arts and Sciences are enormously Perlmutter, of the University of California, Berkeley and Lawrence proud of this most significant accomplishment,” said Dean Katherine Berkeley Laboratory, who worked with a separate team. Newman. “This type of internationally recognized achievement By examining supernovae from more than five billion light years illustrates all that Johns Hopkins is about: the quest for knowledge, away, Riess played a pivotal role in demonstrating that the expansion the drive for discovery, and the passion to make a difference in the rate of the universe is increasing. In 1929, astronomer Edwin Hubble world.” showed that the universe is expanding, but this expansion was ex- The Department of Physics and Astronomy is now home to pected to slow due to the gravitational pull of matter in the universe. In two Nobel Prize winners: Riess and Professor Riccardo Giacconi, who attempting to detect that expected decrease in the expansion rate, the received the Nobel Prize in physics in 2002 for his pioneering work in Nobel winners revealed just the opposite: an accelerating expansion. the field of X-ray astronomy.