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Moiré superlattices formed from transition metal dichalcogenide (TMDC) heterostructures have emerged as a compelling platform for exploring quantum many-body physics. These systems are viewed as a solid-state counterpart to ultracold atomic gases in optical lattices for quantum simulation. A central open question concerns the coherence and dynamics of quantum phases arising from photoexcited moiré excitons, especially under dissipative conditions.

To address this, we employed transient photoluminescence and ultrafast reflectance microscopy to directly image non-equilibrium exciton phase transitions in twisted WS2/WSe2 heterobilayers. Surprisingly, both experimental data and theoretical modeling reveal that strong long-range dipolar repulsion between moiré excitons leads to a freezing of exciton motion in the Mott insulator phase, persisting for over 80 ns. This result defies the conventional expectation that repulsive interactions delocalize particles, while attractive ones promote binding. The observed phenomenon of frozen dynamics due to strong repulsive interactions is characteristic of highly coherent systems, a feature previously realized exclusively in ultracold gases.

We further investigated the interplay between exciton and charge orders in Bose-Fermi mixture, as well as ballistic exciton flow driven by generalized electron Wigner crystals, revealing rich and tunable excitonic correlations in moiré systems.

Io, the innermost Galilean satellite of Jupiter, is the most volcanically active body in the Solar System. Its atmosphere is primarily composed of SO₂, S, O, and SO, and is continuously bombarded by plasma from the Io torus at a relative velocity of ~ 60 km/s. As a result of this strong plasma–atmosphere interaction, Io constitutes a major source of neutrals for the Jovian magnetosphere, the ultimate source of its plasma and the main driver of its dynamics. Despite decades of observations and modeling efforts, many fundamental properties of Io’s atmosphere—its spatial distribution, temporal variability, and loss mechanisms—remain poorly constrained. As this is a promotion seminar, I will focus primarily on the big-picture description of the plasma–atmosphere interaction at Io. I will begin with a brief overview of the Jovian magnetosphere and the four Galilean satellites, before concentrating specifically on Io. I will then describe the complexity and diversity of the physical processes pertaining to Io’s plasma/atmosphere interaction and insist on its primordial role within the Jovian magnetospheric system. Finally, I will present my modeling approach to this interaction, based on multi-species physical chemistry, and briefly review selected publications that highlight my original contributions to the field, as well as outline directions for my future research

All chemical reactions are controlled by species we rarely detect: short-lived carbenes, radicals, and ketenes steer reaction pathways and ultimately determine selectivity and yield. Conventional tools such as GC/MS or NMR usually miss intermediates, even though mechanistic insight is urgently needed for rational process optimization.
In this seminar, I introduce operando Photoelectron Photoion Coincidence (PEPICO) spectroscopy with vacuum ultraviolet (VUV) synchrotron radiation at the Swiss Light Source as a multiplexed approach to reaction analysis. By detecting both ions and electrons after VUV ionization, PEPICO connects mass spectrometry with isomer-selective photoelectron fingerprints, allowing us to disentangle complex reaction mixtures.
I will illustrate how this approach changes our mechanistic understanding in heterogeneous catalysis and high-temperature chemistry, including zeolite-catalyzed plastic pyrolysis, where we identify mechanistic routes to benzene, toluene, and xylenes. Moreover, we turn to biomass conversion, where transient ketenes are the unwelcome guests that steer selectivity off-target.
I will leave you with a practical sense of what intermediates we can observe, how spectra are interpreted, and where operando detection can unveil new mechanistic insights.

I will discuss NASA's Lucy mission, which is the first reconnaissance of the Jupiter Trojan asteroids. Asteroids are the leftovers from the age of planet formation. But, unlike the planets themselves, they have remained relatively unchanged since they formed. As a result, they hold vital clues to how our Solar System formed and evolved, and thus can be considered the fossils of planet formation. Lucy will visit eight of these important objects between 2027 and 2033. It will use a suite of remote sensing instruments to map geologic, surface color and composition, thermal and other physical properties of its targets at close range. Lucy, like the human fossil for which it is named, will revolutionize the understanding of our origins.

TBA

Join CU Wizards Professors Eleanor Hodby and Steven Pollock, along with Gwen Eccles, as they dive into the fascinating world of light, color and color perception - where physics and biology meet!

Mineralogy as a discipline has established the principles of crystal structure, symmetry, and chemistry that dictate all of modern material science underlying everything from computers to photonic technologies operating based on quantum mechanical principles. However, nature itself also acts a laboratory assembling naturally occurring minerals that exhibit even exotic quantum phenomena. I will discuss examples such as natural superconductors, strange metals, or spin liquids which result from the interplay of the quantized nature of electrons, spin, and lattice. I will conclude with a general perspective on how nature inspires and teaches us about intriguing physical phenomena that surround us, often in plain sight

The Department of Biochemistry invites professors and scientists from other universities and institutes to present seminars at the University of Colorado Boulder throughout the academic year. These seminars provide an opportunity for faculty and students to learn about exciting current research.

The Department of Biochemistry invites professors and scientists from other universities and institutes to present seminars at the University of Colorado Boulder throughout the academic year. These seminars provide an opportunity for faculty and students to learn about exciting current research.

Almost exactly 100 years ago, in the early months of 1926, Erwin Schrödinger published a series of four papers that would transform not only the prevailing theories of physics but also mankind’s very understanding of the nature of reality.  Though his work indisputably built upon the ideas of countless others, these papers crystalized the central and most astounding claim of what has become modern quantum mechanics: that at its heart, nature can be understood not as a collection of particles interacting in space but as the endless oscillation of an unseen “wavefunction,” which silently tallies and updates the probabilities of future events. In this talk, we will discuss the historical backdrop of these four transformative papers and then unpack the mathematical and physical innovations they contain (no background knowledge of math or physics is assumed). Finally; we will trace their centennial trajectories through the ensuing years, to reveal the enduring importance of these timeless papers, whose insights—and mysteries—have both only deepened with age. 

The Department of Biochemistry invites professors and scientists from other universities and institutes to present seminars at the University of Colorado Boulder throughout the academic year. These seminars provide an opportunity for faculty and students to learn about exciting current research.