CHICAGO PHYSICS 3 Quantum Worlds Welcome to the third issue of Chicago Physics! This past year has been an eventful one for our Department and we hope that you will join in our excitement. In our last issue, we highlighted our Strickland from University of Waterloo, the Department’s research on topological physics, third Maria Goeppert-Mayer Lecturer and the covering the breadth of what we do in this third female Physics Nobel Prize winner. research area from the nano to the cosmic The University has renamed the Physics scale and the unity in the concepts that drive Research Center that opened in 2018 as the us all. In the current issue, we will take you on Michelson Center for Physics in honor of a journey to the quantum world. former faculty member Albert A. Michelson, The year had several notable events. The a pioneering scientist who was the first physics faculty had a first-ever two-day retreat American to win a Nobel Prize in the sciences, in New Buffalo, MI. We discussed various and the first Physics Department chair at challenges in our department in a leisurely, the University of Chicago. The pioneering low-pressure atmosphere that allowed us work of Michelson is fundamental to the field to make progress on these challenges. This of physics and continues to support new retreat also helped us to bond!! We were discoveries more than a century later. pleased that many family members joined This year we also welcomed back our own lunch and dinner. This was immediately David Saltzberg (Ph.D., 1994) as the followed by a two-day retreat of our women annual Zachariasen lecturer who told of his and gender minority students. experiences as the scientific advisor for We were thrilled that John Goodenough, an the wildly popular television show, The Big alumnus of our Physics Department (SM’50, Bang Theory. Phd’52), jointly with M. Stanley Whittingham We celebrate new members of the and Akira Yoshino, was awarded the 2019 Department in this issue. We also celebrate Nobel Prize in Chemistry “for the development here the lives of Riccardo Levi-Setti, Clemens of lithium-ion batteries”. Roothaan, and Courtenay Wright who died The Heising-Simons Foundation has granted during the past year and who left their us $300,000 for an endowment to support indelible imprint on our Department and on the annual Maria Goeppert-Mayer Lecture physics globally. We miss them, and we are Series at the University of Chicago. The proud of them. lectures are given by outstanding women We hope that the stories we share will inspire physicists in honor of Maria Goeppert-Mayer, you to become more involved and engaged in who won the 1963 Nobel Prize in physics for the Department. Please keep in touch and let developing the nuclear shell model while at us know what you think. UChicago and Argonne National Laboratory. We celebrated this news with Donna Yours sincerely, YOUNG-KEE KIM Louis Block Distinguished Service Professor COVER PHOTO: CHENG CHIN, Chair, the Department of Physics Professor Department of Physics, the University of Chicago CHICAGO PHYSICS 3 / QUANTUM WORLDS Dean’s Letter Editor’s Note When I started as Dean of the Physical would not be possible without attention to I am teaching the introductory course Sciences Division in July, NASA was preparing equity, diversity, and inclusion. This fall, in quantum physics this quarter – which we to launch the Parker Solar Probe, a space- the PSD hired a Director of EDI to build on the obstinately title “Modern Physics,” despite craft designed to make critical observations foundation established by our departments, that it is firmly anchored in a revolution of the Sun. The probe is the first NASA institutes, and centers. The Department of that began at the end of the 19th Century. spacecraft to be named after a living person, Physics has been a model for its programming The students’ skepticism reminds me just how my colleague and professor emeritus at the and support of women and underrepresented weird quantum mechanics is, despite that University of Chicago, Eugene Parker. Parker minorities, and we look forward to a continued it is one of the most rigorously tested theories developed the theory of the solar wind in 1955 partnership that ensures all our constituents we have. The revolution continues into what and helped define the field of heliophysics. feel supported and valued. I’m excited and I suppose one might dub “post-modern The timing of this NASA mission seemed proud to serve such a preeminent department physics”, as we now understand that quantum especially significant as I took the helm of a at UChicago and anticipate a future filled with theory pervades the universe, from the very Division with a rich history of shaping and innovation and discovery. small and cold, to the very large and hot. defining fields. There are numerous University In this volume we get a perspective from three of Chicago physicists who have paved the Chicago physics groups on their own work. way for researchers across the globe, ANGELA OLINTO Cheng Chin explains how one can use atoms including Albert A. Michelson, who started the Dean, at nano-Kelvin temperatures to build a Department of Physics, Robert Millikan, Division of the Physical Sciences remarkable laboratory to study quantum Arthur H. Compton, Maria Goeppert-Mayer, phenomena, and even to simulate cosmology. S. Chandrasekhar, Enrico Fermi, Chen Ning Kathy Levin explains how one can coax Yang, Tsung-Dao Lee, and so many more. a superconducting device to make pairs of As Dean of the PSD, I have the unique Majorana fermions, particles that are their opportunity to support the next generation of own antiparticles. And completing the circle, field-defining scientists who are following Savdeep Sethi offers us a tour of how the in these esteemed footsteps. Last year alone, newly discovered “dark energy” may provide researchers in the Department of Physics some guidance as to how our universe might made numerous exciting break-throughs, be selected from the ridiculously large number including recreating cell division outside of a of possible universes that conventional string cell for the first time, catching the rare decay theory allows. of xenon-124, using gravitational waves to provide a measure of the universe’s expansion, and discovering new forms of quantum PETER LITTLEWOOD behavior. This fruitful intellectual environment Contents Exploring Novel Quantum Phenomena of Atoms 8 and Molecules at Ultralow Temperatures Cheng Chin The Excitement Behind Topological Superconductors 12 Kathryn Levin, Fnu Setiawan & Erez Berg The Mystery of Dark Energy 16 Savdeep Sethi New Faces 20 Prizes & Awards 22 Recent Happenings 24 Events 28 Development 29 In Memorium 30 CHICAGO PHYSICS 3 / QUANTUM WORLDS Exploring Novel Quantum Phenomena of optical dipole force. Depending on the wave- the weak- to strong-coupling regimes to a wealth of non-classical behaviors, of high length of the laser, we see that the optical (See Figure 1). Furthermore, one can tune interest to the condensed matter physics and Atoms and Molecules dipole force can either attract or repel atoms. the interactions to simulate another quantum high-energy physics communities. The stronger the laser intensity the larger system. As an example, Cooper pairing of In summary, we have prepared a many-body the dipole force is. An important application electrons in superconductors can be simulated at Ultralow Temperatures quantum system with optical or magnetic of such an optical force is the optical tweezer based on ultracold fermionic atoms with control of its entire Hamiltonian, including (awarded Nobel prize in 2018), where tightly attractive interactions. Many of our experiments CHENG CHIN the potential energy, interaction energy and focused laser beams can attract and make creative use of Feshbach resonances kinetic energy. These controls are all based capture small objects toward the foci of the to discover and explore novel quantum on some form of resonant couplings induced laser beams. Another application is to overlap phenomena, as we will elaborate below. by external fields. The result is a new generic multiple laser beams on the atoms; the Last but not least, the control of kinetic platform of a quantum system with broadly interference of the lasers forms a periodic The availability of atoms cooled to nano-Kelvin temperatures initiates energy beyond the conventional dispersion programmable properties to explore quantum potential on the atoms, called an optical an exploration into a new world where the dynamics of particles E=p2/2m has become a very hot topic physics in different regimes. The platform lattice. In an optical lattice, the atomic motion in quantum gas research. Modifying the is ideal to test theoretical conjectures that are fully governed by quantum mechanics. Quantization of motion, is quantized and can simulate electrons in kinetic energy term of a particle might sound require careful tuning of the parameters. In the a crystal material. matter-wave interference and entanglement, among other bizarre weird, but such non-standard kinetic energy following, I will outline a few stories and future behaviors that defy our intuition are now right in front of our eyes. At UChicago, we developed a new scheme actually underlies the physics of charged directions in which our group is involved In our laboratory, we develop new tools to control the interactions of to generate arbitrary optical potentials based particles in an electromagnetic field, or more based on such quantum simulation platforms. on Digital Micromirror Device (DMD). A DMD generally, baryons in a dynamic gauge field. atoms, and to analyze their evolution. Novel quantum dynamics were One of the most fundamental questions we is equipped with millions of movable micro- In our lab, we specialize on the control ask ourselves is the origin of the complexity observed that offer insight into other phenomena in nuclear physics, mirrors, and is widely used in overhead of dispersion based on resonant modulation in our world.