Past Events

Abstract: Quantum systems subject to both driving and dissipation are ubiquitous in many fields, and often have com

Abstract: The recent launch of JWST is revolutionizing our understanding of exoplanet atmospheres by providing observations at an unprecedented level of detail. In this talk, I will discuss two methods for studying the atmospheres of exoplanets with JWST. First, I will discuss the potential for spectroscopic eclipse mapping with JWST. Spectroscopic eclipse mapping is the only observational technique which allows for simultaneous resolution of the atmosphere in three spatial dimensions: latitude, longitude, and altitude.

Abstract: 1D gases with point contact interactions are special because they are integrable many-body systems, which means that they have many extra conserved quantities, beyond the usual few (energy, momentum, etc.). I will explain how we make bundles of 1D Bose gases in the lab, the various ways we excite them out of equilibrium, and how we use them as model systems for studying quantum dynamics.

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Stellar astrophysics underpins all areas of astronomy - the explosive deaths of massive stars as supernovae enrich their local environments with processed materials, driving subsequent chemical and galactic evolution, while the compact remnants they leave behind determine the rates of gravitational wave events in the Universe. As such, linking massive stars to their cosmic endpoints is a fundamental aim of stellar astronomy.

Abstract: Many consequential chemical processes take place on ultrafast timescales, including molecular vibrations and bond breaking. Measurements that follow ultrafast molecular dynamics in real time are changing our understanding of these processes. We are designing new tools to study ultrafast molecular dynamics and quantum mechanics with the sensitivity enough to study the molecules in molecular beams and the spectral resolution sufficient for vibrational and rotational resolution.

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Despite the remarkable success of the Lambda Cold Dark Matter (LCDM) cosmological model, several challenges have recently emerged. One of the most prominent is the "Hubble tension": the Hubble expansion rate (H_0) measured using the Cepheid-calibrated distance ladder of type Ia supernovae and the value extrapolated from the cosmic microwave background using LCDM disagree by 5 standard deviations.

As a follow-up to Seminar I, I will discuss specific examples of fs UPS and photovoltage experiments on industrially relevant materials and stacks. Aside from single crystal Si wafers, virtually all materials found in MOS devices, photovoltaics, oxides, organic films (OLEDs, resists) and phase change materials, are polycrystalline or amorphous. Angle integrated UPS provides high count rates that increase sensitivity useful for identifying defect state densities in materials.

Abstract: Neutrinos are enigmatic particles. Their properties are rather basic and yet so bizarre and surprising that at times we hardly believe them. We barely notice their presence, and yet they are everywhere and are essential to things as glaring as the sun’s energy production. The minuscule but non-zero mass of a neutrino, nearly a million times smaller than the electron (the next lightest particle), has enormous consequences for our understanding of these particles and their role in shaping the universe.

A major goal of modern particle physics is to search for phenomena that are in conflict with our best theoretical understanding of nature, the Standard Model (SM). One approach in the search occurs at the laboratory scale where the SM’s most precise predictions are tested by the most precise measurements of fundamental particles. Deviations at this high-precision frontier would inform the search for Beyond the SM (BSM) physics.

CU Boulder · JILA X317 | UC Berkeley · Birge 468 Critical to the design and development of present and future semiconductor and quantum devices is the full understanding of the electronic structure of the materials that comprise the complex functional stacks in a non-destructive way. In Seminars I and II, I will describe the application of femtosecond ultraviolet photoelectron and photovoltage spectroscopy (fs UPPS) to fully characterize the electronic structure of industrially important materials and devices.

Abstract: Quantum technologies based on molecules afford unique potential in miniaturization, spatial localization, and tunability through synthetic chemistry. Paramagnetic molecules constitute a platform for implementing quantum bits (qubits) and quantum sensors (qusors). While electron spin decoherence can potentially be leveraged in quantum sensing applications, its use is ultimately limited by spin relaxation, which effectively leaks quantum information into the environment.

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Abstract: Galaxies are a lot like people. If you pay attention to someone’s accent, mannerism, music taste, and cuisine preference — you can infer something about their culture, their heritage, their ancestry. On the same vein, by inspecting a galaxy’s morphology, kinematics and chemical composition — one can infer information about its assembly history, its interaction history. The first part of this talk will focus on extreme galactic collisions, where a small satellite crashes onto the baryonic body of a massive neighbor and survives.