Columbia Quantum Initiative Distinguished Speaker Series
Our Distinguished Speaker Series regularly brings thought leaders in quantum science and technology to Columbia.
Coming Up: Stay Tuned for Announcements for Spring Lectures!
Past Distinguished Speakers
Lecture: Quantum Computing and the Entanglement Frontier
Held on October 13, 2022, in Davis Auditorium
Abstract: The quantum laws governing atoms and other tiny objects seem to defy common sense, and information encoded in quantum systems has weird properties that baffle our feeble human minds. John Preskill will explain why he loves quantum entanglement, the elusive feature making quantum information fundamentally different from information in the macroscopic world. By exploiting quantum entanglement, quantum computers should be able to solve otherwise intractable problems, with far-reaching applications to cryptology, materials, and fundamental physical science. Preskill is less weird than a quantum computer, and easier to understand.
Seminar: Learning in a Quantum World
Held on October 14, 2022, in the Center for Theoretical Physics
Abstract: I will review an experimentally feasible procedure for converting a quantum state into a succinct classical description of the state, its classical shadow. Classical shadows can be applied to predict efficiently many properties of interest, including expectation values of local observables and few-body correlation functions. Efficient classical machine learning algorithms using classical shadows can address quantum many-body problems such as classifying quantum phases of matter. I will also explain how experiments that exploit quantum memory can learn properties of a quantum system far more efficiently than conventional experiments.
Speaker Biography: John Preskill is the Richard P. Feynman Professor of Theoretical Physics at the California Institute of Technology, and Director of the Institute for Quantum Information and Matter at Caltech. Preskill received his Ph.D. in physics in 1980 from Harvard, and joined the Caltech faculty in 1983. Preskill began his career in particle physics and cosmology, but now his main research area is quantum information science. He's interested in how to build and use quantum computers, and in how our deepening understanding of quantum information can illuminate issues in fundamental physics.
Lecture: What Happened to the Kilogram?
Held on May 1, 2023, in Davis Auditorium
Abstract: For 130 years, a cylinder made of a platinum-iridium alloy stored near Paris was the official definition of a kilogram, the basic unit of mass. This all changed on May 20, 2019. A kilogram is now defined by a fundamental constant of nature known as the Planck constant (h), which relates the energy of a photon to its frequency: h= 6.62607015 10-34 kilograms times square meters per second.
The definition of the kilogram is now connected to the definition of time, realized by atom clocks, and the speed of light. Sounds complicated? In this talk, Ketterle will provide the reasons for changing the definition of the kilogram, give simple explanations of what the new kilogram is conceptually, and explain how objects with exactly known masses can be realized using precision measurements and advanced quantum technology.
Seminar: New Platforms for Quantum Science
Held on May 2, 2023, in the Center for Theoretical Physics
Abstract: Ultracold atoms and molecules continue to provide new opportunities for basic quantum science, for precision measurement, and for the study of paradigmatic Hamiltonians, called quantum simulations. I will illustrate two novel systems. Using ultracold NaLi atoms in the triplet ground state, we were able to control chemistry via magnetic fields and quantum interference. Using a new optical superresolution technique, we could localize dysprosium atoms with a separation much smaller than the diffraction limit of light, down to 50 nm, and observe strong purely magnetic interactions between atoms which are usually much weaker than electric interactions.
Speaker Biography: Wolfgang Ketterle has been the John D. MacArthur professor of physics at MIT since 1998. He received a diploma (equivalent to a master’s degree) from the Technical University of Munich (1982), and a Ph.D. in physics from the University of Munich (1986). He did postdoctoral work at the Max-Planck Institute for Quantum Optics in Garching and at the University of Heidelberg in molecular spectroscopy and combustion diagnostics.
In 1990, he came to MIT as a postdoc and joined the physics faculty in 1993. Since 2006, he has been the Director of the Center of Ultracold Atoms, an NSF-funded research center, and Associate Director of the Research Laboratory of Electronics. His research group studies the properties of ultracold quantum matter.
For his observation of Bose-Einstein condensation in a gas in 1995, he received the Nobel Prize in Physics in 2001. Other honors include the Gustav-Hertz Prize of the German Physical Society (1997), the Rabi Prize of the American Physical Society (1997), the Fritz London Prize in Low Temperature Physics (1999), the Benjamin Franklin Medal in Physics (2000), and a Humboldt research award (2009).
Lecture: Quantum Science & Atomic Clocks
Held on September 28, 2023 in Davis Auditorium
Abstract: Quantum state engineering, many-body physics, and innovative laser technology are revolutionizing the performance of atomic clocks and metrology, providing opportunities to explore emerging quantum phenomena and probe fundamental physics. Recent advances include precise control of atomic interactions to achieve high accuracy, determination of gravitational time dilation across a few hundred micrometers, and employment of spin entanglement for clock comparison.
Seminar: Quantum Science of Molecules with Modern Twists
Held on September 29, 2023, in the Center for Theoretical Physics
Abstract: New observation and control tools for molecules are providing powerful opportunities to study complex structure, interaction dynamics, and their applications to fundamental discovery and practical sensing needs. Meanwhile, quantum gases of polar molecules offer precisely tunable many-body systems to explore emergent quantum phenomena such as magnetism.
Speaker Biography: Jun Ye is a Fellow of JILA, a Fellow of NIST, and a member of the National Academy of Sciences. His research focuses on the development of new tools for light-matter interactions and their applications in precision measurement, quantum science, and frequency metrology. He has co-authored over 400 scientific papers and delivered 600 invited talks. Among his many awards and honors are N.F. Ramsey Prize (APS), I.I. Rabi Award (IEEE), I.I. Rabi Prize (APS), and W.F. Meggers Award (OSA). His recent 2022 honors include Breakthrough Prize in Fundamental Physics, Niels Bohr Institute Medal of Honour, Herbert Walther Award, and Vannevar Bush Fellowship.
Lecture: No Strain, No Gain. Modifying 2D Materials by Engineering Strain
This was a joint event with the Physics Department's C.S. Wu Colloquium held on January 29, 2024 in Davis Auditorium.
Abstract: Applying strain can drastically modify the properties of electronic materials–for example, strained silicon transistors showed huge mobility increases that revolutionized the computer industry. Now, there is wide interest in using strain to modify the next generation of electronic materials: two-dimensional systems. 2D materials bridge the limits of superior electric tunability and high mechanical flexibility, making them excellent candidates for mechanical tuning of electronic properties. Strained graphene, in particular, is predicted to manifest a bandgap opening as well as novel physical effects such as large “pseudo”-magnetic fields. However, it is challenging to create global strain across graphene to modify transport. In this talk, we demonstrate how controllable, global strain in graphene can be engineered by depositing graphene on corrugated substrates. We show that strained graphene exhibits bandgap openings and pseudomagnetic field effects that depend on the magnitude of induced strain. Control of the strain degree of freedom provides a novel platform both for fundamental studies of 2D electron correlations and for prospective application in 2D electronic devices.
Watch the recording here.
Speaker Biography: Nadya Mason is the Dean of the Pritzker School of Molecular Engineering at the University of Chicago