2022
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Tuesday, December 13, 2022 Join our December graduating seniors as the present their work! |
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Friday, December 9, 2022 Hegeman 107 12:00 pm – 1:00 pm EST/GMT-5 Our research group at MSU, the Laboratory for Hybrid Quantum Systems, works on wide variety of experiments at the boundary of condensed matter physics (CMP) and quantum information science (QIS) to create hybrid/synthetic quantum systems with novel properties and/or functionality. The ability to imagine and create these types of quantum systems, which bring together seemingly disparate (but interacting) degrees of freedom, brings the exciting possibility of unexpected discoveries and new directions in fundamental and applied quantum research in systems ranging from many-electron fluids & solids to tailor-made artificial atoms based on superconducting circuits. In this talk I will describe our work on creating novel hybrid quantum systems that integrate superconducting qubits + superfluids, electrons trapped on the surface of liquid helium, and surface acoustic wave (SAW) devices. By leveraging the precision experimental techniques of QIS our experiments reveal insights into the coherence properties of established superconducting qubit systems & single electron devices and potential methods for improving their coherence. Our experiments also open the door to developing altogether new qubits and high-frequency SAW devices based on electrons trapped on the surface of superfluid helium as well as new regimes of circuit quantum optics using piezo-phonons. |
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Friday, November 18, 2022 Hegeman 107 12:00 pm – 1:00 pm EST/GMT-5 The possibility to isolate atom-thick layer of material from a bulk crystal allows the design of structures with a wide range of properties. In particular, by twisting those single layer sheets, a periodic potential, called moiré potential, is superimposed over the lattice modifying the properties of the parent material. Twisted two-dimensional materials have generated tremendous excitement as a platform for achieving quantum properties on demand. However, the moiré pattern is highly sensitive to the interlayer atomic registry, and current assembly techniques suffer from imprecise control of the average twist angle, spatial inhomogeneity in the local twist angle, and distortions due to random strain. Here, we demonstrate a new way to manipulate the moiré patterns in hetero- and homo-bilayers through in-plane bending of monolayer ribbons, using the tip of an atomic force microscope. This technique achieves continuous variation of twist angles with improved twist-angle homogeneity and reduced random strain, resulting in moiré patterns with highly tunable wavelength and ultra-low disorder. Our results pave the way for detailed studies of ultra-low disorder moiré systems and the realization of precise strain-engineered devices. |
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Friday, November 11, 2022 Hegeman 107 12:00 pm – 1:00 pm EST/GMT-5 Physicists use abstract mathematics to describe, and advanced technologies to probe, the physical world on spatial, temporal, and complexity scales unperceivable by the human body through ordinary perception. How, then, does a physicist – a living, breathing organism whose primary knowledge is rooted in the physical interaction of their body with the physical world – work with abstract objects and ground their understanding in the sensory impressions and emotional states that their body makes possible? In this talk, I will sketch out a research program that integrates artistic and intellectual practice to guide our approach to this question. My work is informed by the history and philosophy of science, theories of embodied and situated cognition, and Maurice Merleau-Ponty’s philosophy of phenomenology. My aim is to gain a more intimate understanding of the individual experiences of scientific inquiry and to explore their impact on collective research efforts in physics. |
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Friday, November 4, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 The Event Horizon Telescope (EHT) is a network of eleven millimeter-wavelength radio telescopes that spans the globe from Greenland to the South Pole. Using the technique of Very Long Baseline Interferometry (VLBI), the EHT combines data from these telescopes to produce images with resolution comparable to that of a single telescope with the Earth’s diameter. The EHT has imaged both the supermassive black hole in the giant elliptical galaxy M87 and Sagittarius A*, the black hole in our Galactic Center. These images show rings of light produced by extremely hot, magnetized plasma with sizes very similar to that of the black hole's theoretical ‘shadow.’ Producing these images required years of painstaking calibration, validation, and imaging of EHT data, as well as new advances in numerical simulations required to model the turbulent plasma inflows and outflows around black holes. In this talk, I will discuss how the EHT obtained its images and how we use them to understand the extreme environments around supermassive black holes. I will also discuss how future advances in both EHT observations and theoretical simulations will both reveal the connection between supermassive black holes and extragalactic jets and enable more precise tests of General Relativity near the black hole boundary. |
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Friday, October 28, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 The Galactic Center (GC) is a unique environment with the highest concentration of stars, gas and compact objects (black holes, neutron stars and white dwarfs) in our galaxy. The central parsec region contains about 10 million stars, while the closest star to Earth is located at about 1 parsec away. Due to the long distance (8 kiloparsecs) and a large amount of gas and dust in between, the GC region is invisible in the optical band and its true nature remained elusive for many years. Over the last two decades, a new generation of radio, infrared and X-ray telescopes has revolutionized our understanding of the GC region, as manifested by the 2020 Nobel Prize in Physics awarded for the discovery of a 4 million solar mass black hole at Sagittarius A*. In the X-ray band, NASA’s Chandra telescope detected over 10,000 X-ray emitting sources in the GC region. I will present our recent investigations on the X-ray sources, most of which contain compact objects, in the central parsec to over 100 parsecs away from Sagittarius A*. I will highlight several exciting discoveries and discuss some implications on how the formation, dynamics and evolution of compact objects are controlled by immense gravity from the supermassive black hole and interactions with stars. |
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Friday, October 21, 2022
Reem-Kayden Center 4:00 pm – 6:00 pm EDT/GMT-4
Join our summer research students as they present their work! Download: BSRI abstract booklet F22-3.pdf |
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Friday, October 14, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Over the last few decades, scientists have found thousands of planets beyond our own. Some of those planets might be habitable, and perhaps even inhabited already; but how can we tell? Clara Sousa-Silva looks for signs of life on other planets using astronomical tools to detect faint signals emitted by potential alien biospheres. In this presentation, Clara draws on her experience investigating strange molecules on strange planets, and her efforts to answer the question: "Would we know life if we saw it?" The work presented in this talk combines organic chemistry and quantum mechanics as tools for the interpretation of astrophysical spectra and, ultimately, the detection of life on an exoplanet. Whether alien life will produce familiar gases (e.g., oxygen) or exotic biosignatures (e.g., phosphine), painting a confident picture of a potential biosphere will require a holistic interpretation of an atmosphere and its molecules. In this talk Clara will describe ongoing efforts to train the next generation of scientists to decipher exoplanet atmospheres, and ultimately to detect a biosphere through the identification of atmospheric molecules, in particular those that might be produced by non-Earth-like life. Professor Sousa-Silva is is a quantum astrochemist and molecular astrophysicist. She investigates how molecules interact with light so that they can be detected on faraway worlds. Clara spends most of her time studying molecules that life can produce so that, one day, she can detect an alien biosphere. Her favorite molecular biosignature is phosphine: a terrifying gas associated with mostly unpleasant life. When she is not deciphering exoplanet atmospheres, Clara works hard to persuade the next generation of scientists to become an active part of the astronomical community. Clara holds a doctoral degree in quantum chemistry from the University College London, and a masters degree in physics and astronomy from the University of Edinburgh in Scotland. Among her many achievements, Clara is the recipient of the prestigious 51 b Pegasi Fellowship from the Heising Simons Foundation. The fellowship supports the growing field of planetary astronomy and exceptional postdoctoral scientists who make unique contributions to the field of astronomy. Prior to joining Bard College, Clara was at the Center for Astrophysics | Harvard & Smithsonian from 2020 - 2022, and MIT from 2016 - 2020. Clara’s work and commentary has been featured in the BBC, WIRED, and the New York Times, among many others, and is the focus of her TED talk. |
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Friday, October 7, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 This year's Nobel Prize in physics was awarded jointly to John Clauser, Alain Aspect, and Anton Zeilinger for their pioneering work testing some of the more surprising predictions of quantum mechanics and helping to establish the burgeoning field of quantum information. In this talk, aimed at a general audience, I'll discuss the 100-year history of a philosophical conundrum about the nature of reality, debated by Niels Bohr and Albert Einstein, that the laureates resolved experimentally. Along the way, we'll see how political exiles, social outcasts, bankrupt science journals, and scavenged lab equipment all contributed to laying the groundwork for a "second quantum revolution" that's currently underway. |
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Friday, September 16, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Using optically levitated nano-spheres, the Geraci group at Northwestern University's Center for Fundamental Physics (CFP) makes precision measurements with the scientific goal of investigating fundamental aspects of gravity and quantum foundations. To search for effects of gravity at short ranges, we employ a dual beam optical trap to confine 300nm fused silica spheres in an optical potential. The sphere is then brought within microns of a driven oscillating mass with a periodic density structure. This oscillating mass causes the motion of the trapped nano-sphere to change as a result of gravitational interaction, and the gravitational force exerted on the nano-sphere is then measured by using imaging techniques to track its motion in the optical trap. This type of system has already shown zepto-newton force sensitivity, and is currently being updated to have even higher sensitivity as well as the capability to search for Casimir-Polder forces. Additionally, I will describe an experiment which plans to investigate quantum properties of these nano-spheres by using matter-wave interferometry. To do so, we must first cool the center of motion of the bead to its motional ground state using parametric feedback cooling. Successfully observing quantum properties of these nano-spheres will potentially open the door to a regime of physics where macroscopic objects can be put into quantum superpositions, allowing for tests of quantum foundations and the quantum to classical transition. |
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Tuesday, May 17, 2022 Abstract booklet below! Download: Senior Project Poster session booklet S22-1.pdf |
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Friday, May 6, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Albert Einstein predicted gravitational waves in 1916, as a consequence of his general relativity theory. A century later, the Laser Interferometer Gravitational-Wave Observatory (LIGO) began observing these waves from merging systems of black holes and neutron stars. These observations cemented relativity theory and inaugurated an era of gravitational-wave multi-messenger astronomy. LIGO and its partners are just sensitive enough to measure the strongest gravitational waves. Cosmic Explorer (CE) is a next-generation ground-based gravitational-wave observatory envisioned to begin operations in the 2030s. With its spectacular sensitivity, CE will peer deeply into the universe’s dark side — observing gravitational waves from remnants of the first stars — and open a wide discovery aperture to the novel and unknown. |
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Friday, April 29, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Galaxy mergers and interactions are thought to play a key role in the evolution of galaxies. These collisions can affect many important galaxy properties, such as their physical structure, their star formation rates, and the growth of their central black holes. However, the details of this role, and how it has changed over the age of the Universe, is still a matter of much debate. Both theoretical models and some recent observations have suggested that mergers do not play a dominant role in the early Universe, but that instead much of the mass growth of galaxies and their black holes can be attributed to secular processes such as disk instabilities. I will present the results of a detailed, multiwavelength analysis of galaxy mergers and interactions and their impact on star formation and black hole growth via AGN. I will also discuss plans for future work using the James Webb Space Telescope. |
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Friday, April 22, 2022
Beate G Liepert, EUS Program
Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Air pollution is well known as a public health problem, but not so such as a climate change driver. Only recently has the term “aerosols” entered public consciousness as a pathway with which the corona virus spreads. For atmospheric scientists however, aerosols (i.e., particulate matter) have been well known as one of the key uncertainties in climate change, due to their direct effect of reflecting solar energy back to space, and aerosol-cloud interactions. The presentation provides an overview of the role of aerosols in climate from an observational and a modelling point of view. The wickedness of the problem will become clear, when air pollution is reduced and as a consequence, global warming unmasked. |
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Friday, April 15, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Our ability to successfully forecast changes in climate relies on fundamental physical concepts – including radiative transfer, conservation laws, chemistry, and fluid dynamics – but much of the structural uncertainty in climate model projections relates to more empirical aspects of parameterizations of unresolved processes, such as cloud nucleation, ocean eddy mixing, and convection. There is an apparent tension between the confidence we have basic physics and the specifics of projected changes using these models. Other uncertainties relate to scenarios for important emissions (such as carbon dioxide, methane, and ozone and aerosol precursors), and the fundamentally chaotic nature of the weather (though not the climate). I will discuss the ways in which we can build confidence for the use of these models in assessing climate risk though the use of out-of-sample test case, hindcasts, multi-variate assessments and success in real forecasts. |
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Friday, April 8, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 X-ray emission has long been observed from giant molecular clouds located in the galactic center region of our Milky Way. These molecular clouds are thought to be reprocessing past X-ray outbursts from supermassive black hole Sgr A*. By studying the clouds’ flux over time, we are able to reveal the past outburst activities of Sgr A* hundreds of years ago. I have been utilizing newly received NuSTAR and archival XMM-Newton observations of the “Bridge” molecular cloud in order to present a 20-year-long light curve of the cloud’s flux. This data reveals that the X-ray luminosity of the “Bridge” cloud has been monotonically increasing since ~2007, almost doubling in the last decade, and provides strong evidence of an outburst light front from Sgr A*. In this seminar, I will discuss aspects of the data analysis process, present results, and touch on my post-Bard experiences. |
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Friday, April 1, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Stellar explosions and colliding neutron stars are important sources of the chemical elements in nature. While some of the astrophysical processes responsible for element creation are well understood, others have remained elusive for decades. Processes creating elements often involve short lived radioactive isotopes that can be produced at accelerator facilities. Studies with these isotopes allow us to constrain the relevant nuclear reaction rates and nuclear properties so one can understand in the laboratory how elements are created. Recent progress in astronomical observations, such as the observation and verification that the merging of two neutron stars is as a source of heavy element production in the Universe, need to be accompanied with similar progress in understanding the relevant properties of rare isotopes through nuclear physics experiments. I will review the important role that rare isotopes play in understanding stellar explosions, show some examples of recent nuclear physics measurements and give a (very abbreviated) outlook of future nuclear astrophysics studies. |
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Friday, March 11, 2022 Hegeman 107 12:00 pm – 1:00 pm EST/GMT-5 These days it seems like everyone has an interest in astronomy. Young kids are watching YouTube videos about black holes, adults are participating in astronomy-themed lifelong learning courses, and thousands of people across the globe watched James Webb launch on Christmas morning. It’s important for educators and professionals to nurture this passion for astronomy in our community, in hopes of encouraging more people to pursue a career in the sciences. In this talk, I’ll share some of my research efforts in the area of star and planet formation and discuss how my initial career in science communication inspired me to develop an observational astronomy research program at SUNY Oneonta. I will also talk about my current outreach efforts throughout New York state, and my upcoming series with The Great Courses that’s designed to teach amateur astronomers how to get involved in Citizen Science. By providing students, amateur astronomers, and the general public with the skills and cosmic knowledge they yearn to acquire, we can set them on a path towards tackling some of the big unanswered questions about our Universe. |
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Friday, February 25, 2022
Ivy Li, Rice University
Hegeman 107 12:00 pm – 1:00 pm EST/GMT-5 The Universe contains vastly more dark matter than baryonic matter, and yet dark matter's particle nature remains elusive. The challenge of discovering dark matter's particle nature has spurred a technological race around the world. Scientists build experiments to hedge their bets on measuring dark matter, all while developing computational methods to face ongoing Big Data challenges. One such dark matter experiment is XENONnT, a xenon time projection chamber located underground at the Laboratori Nazionali del Gran Sasso in Italy. XENONnT has already collected petabytes of data and will continue to do so; in the upcoming years, storing, processing, and analyzing such data has become both a physics and a computational problem. In this talk, I will discuss our current understanding of dark matter, introduce the XENONnT experiment and its dark matter search, and explore two computational aspects of its setup: data processing on Open Science Grid and data compression for managing petabytes of data. Finally, I will highlight ongoing work from our interdisciplinary group at Rice, particularly machine-learning applications for astroparticle physics, and share a bit about my pathway into physics. |
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Friday, February 11, 2022
Andrew Harder, Lehigh University
Hegeman 107 12:00 pm – 1:00 pm EST/GMT-5 An elliptic Lefschetz fibration is a smooth 4-manifold M (possibly with boundary) which admits a map to a surface S (possibly with boundary), and so that all but a finite number of fibers are diffeomorphic to a 2-torus, and the rest are homeomorphic to a “pinched” 2-torus. The classification of elliptic Lefschetz fibrations can be reduced to a (hard) problem in linear algebra whose solution is known in several cases — for instance, a theorem of Moishezon and Livné says that if S is just the 2-sphere then it is known that any elliptic Lefschetz fibration has 12n fibres which are pinched 2-tori for some integer n, and that the topology of M is completely determined by n. Surprisingly, the situation where S is a 2-dimensional disc, despite being well studied, is not completely understood. In this talk, I will discuss an answer to this problem under certain conditions on the boundary of M and on the number of fibres which are singular. We reduce this problem to a question about linear algebraic objects called pseudo-lattices and apply a theorem of Kuznetsov to give a concrete description of a class of elliptic Lefschetz fibrations. Finally I will discuss my motivation for considering this problem and how this classification theorem reflects the numerical classification of weak del Pezzo surfaces in algebraic geometry. This is based on joint work with Alan Thompson. |