Harvard University Department of Physics Newsletter FALL 2020 Physics In The Time Of Coronavirus also in this issue: Radioastronomy’s First Spectral Line John Doyle: Trapping and Cooling Molecules Christopher Stubbs: A Dean for All Seasons Cora Dvorkin: Digging into the History of the Cosmos A Tribute to Carol Davis ON THE COVER: The Department Hundreds of boxes CONTENTS of lab kits are ready Today: for shipment at the Instructional Physics Labs Letter from the Chair ....................................................................................................................2 Inset: Lab kit for Physics 16 176 FACULTY HIGHLIGHTS Undergraduate concentrators Promotions and New Faculty......................................................................................................3 Faculty Prizes, Awards, and Acknowledgments ......................................................................6 Books by Faculty ...........................................................................................................................7 248 COVER STORY Graduate students Physics in the Time of Coronavirus .............................................................................................8 78 HISTORICAL FOCUS Radioastronomy’s First Spectral Line: A Glimpse of the Handiwork of Creation ..............14 Postdoctoral fellows FEATURED 125 -RKQ'R\OH7UDSSLQJDQG&RROLQJ0ROHFXOHVDVD3DWKWR6FLHQWLÀF$GYDQFHPHQW .....20 Christopher Stubbs: A Dean for All Seasons ...........................................................................27 Other research scholars Cora Dvorkin: Digging into the History of the Cosmos ..........................................................32 9 ACADEMIC PROGRAMS Undergraduate Program ...........................................................................................................35 Non-ladder faculty members Graduate Program .....................................................................................................................38 Research Scholars ......................................................................................................................43 ACKNOWLEDGMENTS 5 Newsletter Committee: CELEBRATING STAFF Tenure-track faculty members Professor Roxanne Guenette Professor Paul Horowitz A Tribute to Carol Davis .............................................................................................................44 Professor Efthimios Kaxiras Professor Matthew Reece 46 Professor Subir Sachdev Professor Xi Yin Tenured faculty members Mary McCarthy Anne Trubia 34 Production Manager: Staff members Marina Werbeloff 2 PHYSICS AT HARVARD FALL 2020 1 FACULTY HIGHLIGHTS Letter from the Chair Faculty Promotion Dear friends of Harvard Physics, On page 14, you will find a fascinating essay on Daniel L. Jafferis of supersymmetric renormalization group (rg) Harold Ewen and Edward Purcell’s first detection flows in three dimensions.2 A year later, in 2011, It’s a pleasure to present to you the seventh annual of the 21 cm emission from neutral hydrogen in together with Igor Klebanov, Silviu Pufu and Physics Newsletter, created with care and The department of physics is pleased to announce the Milky Way, “Radioastronomy’s First Spectral Benjamin Safdi, he conjectured a monotonicity enthusiasm by our Newsletter Committee. the promotion of Daniel L. Jafferis to Professor of Line,” by Paul Horowitz, Professor of Physics and property for such rg flows, named the F-theorem.3 Physics with tenure. What a year this has been! In previous editions, my of Electrical Engineering, Emeritus, and our These discoveries led to a stream of research that predecessors opened his letter with lyrical in-house historian extraordinaire. Daniel was home schooled until the age of 14, significantly advanced our understanding of references to our campus’ beauty in spring or fall I hope you will enjoy articles on the ground- when he enrolled at Yale University, from which supersymmetric gauge theories and dualities in weather. As I write this letter, most of us have not breaking work of Henry B. Silsbee Professor of he graduated in 2001 with a B.S. in physics. He three dimensions. been on our beloved campus for what seems like an Physics John Doyle and Associate Professor of proceeded to earn a Ph.D. in physics from eternity. The Spring 2020 term had barely reached Together with his then-graduate student Ping Physics Cora Dvorkin, written by Steve Nadis and Harvard in 2007 and did postdoctoral work at its midpoint when the university announced that Gao and Aron Wall of IAS, Princeton, Jafferis Juan Siliezar, respectively. We have also included a Rutgers University, the Institute of Advanced 4 all classes were to transition online, and most wrote another ground-breaking paper, which report, by Mary McCarthy, on the retirement Study (IAS) in Princeton, and Harvard. He was activities on campus to cease immediately, to ensure demonstrated that wormholes linking different celebration of our beloved and indomitable Carol appointed an Assistant Professor of Physics at everyone’s safety in the face of the rising tide of the regions of spacetime can be traversable (a feature Davis. Over a 50-year career in our department, Harvard in 2013. COVID-19 pandemic. long thought to be impossible) in a setting where Carol has supported and nurtured many genera- A theoretical physicist whose primary research the averaged null-energy condition is violated by As difficult as this time was (and continues to be), tions of undergraduate and graduate students, areas are quantum field theory, string theory, and known quantum effects. Furthermore, these there is much to celebrate. Thanks to the making a huge difference in their lives and careers. quantum gravity, Jafferis has made several major traversable wormholes have a dual description in dedication, hard work, and community spirit of all We are all thankful to Carol for her contributions contributions to those fields. terms of quantum teleportation. This work is not members of our department, and despite the and will sorely miss her ebullient presence. only thought-provoking for theorists working on challenges the pandemic has thrown our way, we In 2008, as a postdoc in Rutgers, he penned an To our disappointment, health and safety concerns quantum gravity, but also raises a possible way of have managed to continue our mission of teaching 1 forced the department to cancel plans ),5the influential paper with Ofer Aharony, Oren and research with minimal interruptions. Classes testing the surprising predictions of quantum Spring 2020 Physics Graduate Alumni Reunion. Bergman, and Juan Maldacena, proposing the are going on remotely and many report a high level gravity on the relation between entanglement and Since then, some of you expressed interest in a ABJM theory of M2 branes. M-theory, a unifying of student engagement; most of the experimental the connectivity of space through construction of smaller annual gathering of alumni and graduate framework for superstring theories, has a limit in lab work has resumed, albeit at a slower pace and the dual quantum systems. students during the Commencement festivities. which it contains gravitons propagating in with many restrictions; and our theory colleagues We would love to hear from more alumni whether eleven-dimensional spacetime, as well as Daniel’s achievements have been recognized by diligently continue to work from home, even you would be interested in such an annual event. membranes whose dynamics were previously little numerous prizes and awards, such as the inaugural though the joy of this work is nowhere close to understood. Their paper provided a breakthrough 2012 Henry Primakoff Award for Early-Career what everyone experienced on campus. As courses of instruction will continue to be in this understanding by offering the long-sought Particle Physics from the American Physical delivered remotely for the Spring 2021 semester, it To find out how our department responded to this Lagrangian description of the M-theory Society “for the construction and study of is likely that the 2021 Commencement celebration unprecedented crisis, please read the cover story, membranes, and an exact duality between three-dimensional supersymmetric quantum field will also be moved online. By now, most of us are “Physics in the Time of Coronavirus,” by Steve M-theory in four dimensional anti de Sitter theories,” and a 2014 Alfred P. Sloan Research old hands at Zoom gatherings, and plans for the Nadis, and a feature article by Clea Simon on spacetime and a supersymmetric Chern-Simons- Fellowship in Physics. In 2019, he was also online festivities are underway. We will notify you Christopher Stubbs, Samuel C. Moncher Professor matter theory in three dimensions. awarded a New Horizons in Physics Prize “for of the particulars in the spring. of Physics and of Astronomy and Dean of Science, fundamental insights about quantum information, In 2010, while at IAS, Princeton, Jafferis whose leadership played a crucial role in the success And of course, we are always happy to hear from quantum field theory, and gravity.” of Harvard’s response to the pandemic: A Dean for you, so please don’t hesitate to contact us with any discovered a method for exactly calculating All Seasons.” comments or suggestions, or simply to say “hello” properties of strongly coupled infrared fixed points to old friends. In other positive news in the face of the pandemic, the departmental Equity and Inclusion Committee, Warm wishes, led by Donner Professor of Science