Past Events

Abstract: The mineralogy of our planet is a fingerprint of history—a durable archive of the physical and chemical conditions that have evolved over 4.5 billion years. Minerals record temperatures and pressures, redox states and fluid compositions, preserving evidence that spans the earliest violent collisions of solar-system formation to human activities that occurred only yesterday. Yet Earth’s mineral story reaches far deeper in time, extending back to the very origins of the elements themselves.

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.

Nuclear spins are usually not thought to participate in chemical reactions. However, in the ultracold temperature regime, we have a new opportunity to examine this general statement with quantum mechanical details. In this talk, I will present our ongoing investigations into the roles of nuclear spins, quantum coherence, and entanglement in molecule-molecule reactions and atom-molecule collisions, utilizing a one-of-a-kind ultracold KRb molecule apparatus inspired from the original set of JILA KRb experiments 17 years ago.

The interaction of the electronic spin and molecular vibrations mediated by spin-orbit coupling governs spin relaxation in molecular qubits. We derive a dynamic molecular spin Hamiltonian that includes both adiabatic and non-adiabatic spin-dependent interactions, and we implement the computation of its matrix elements using density functional theory. The dynamic molecular spin Hamiltonian contains a novel spin-vibronic interaction with non-adiabatic origin in addition to the conventional molecular Zeeman and dipolar spin interactions with adiabatic origin.

The evolutionary history, and likely habitability, of exoplanet atmospheres depends on the space weather of their host stars. Understanding the particle environment, including the wind density, magnetic field strength, and velocity field, impinging on exoplanet systems remains a significant open question. This unknown impacts the interpretation of exoplanet atmosphere observations and the ongoing search for biosignatures, with facilities like JWST.

Synchronization—the spontaneous emergence of phase coherence among interacting oscillators—is a ubiquitous phenomenon in classical systems, from pendulum clocks to biological rhythms. In quantum systems, however, coherence is fragile, and environmental noise is usually viewed as its primary adversary. This colloquium explores a counterintuitive regime in which noise itself becomes a resource, driving rather than destroying coherent behavior.

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.

Remote sensing of the universe, including Earth and its atmosphere, largely relies on extracting information from photons/electromagnetic waves. To optimize information extraction, instruments and data analysis have to be looked at as a system. The colloquium will highlight examples of this systems approach to optical instrumentation that I have been involved in over the past few decades.

Surfaces and interfaces play a crucial role in chemical and physical phenomena, such as heterogeneous catalysis and reactions. At the surface or interface of water, the hydrogen-bonded network is abruptly interrupted, giving rise to fascinating interfacial properties. These specific properties are the driving forces for many biochemical, environmental and geochemical processes.

Rydberg atoms in optical tweezers have become a leading platform for both quantum simulation and quantum computing. However, they are often limited by their relatively short lifetime of a few tens of microseconds. One way to overcome this limitation is to use Rydberg atoms with maximum angular momentum (m = l = n-1), known as circular states. When placed in a cryogenic environment, these states can exhibit lifetimes of several milliseconds. Circular states of alkaline-earth-like atoms offer additional advantages.

The promise of universal quantum computing hinges on scalable single- and inter-qubit control interactions. Photon systems offer strong isolation from environmental disturbances and provide speed and timing advantages while facing challenges in achieving deterministic photon-photon interactions necessary for scalable universal quantum computing.

Solar irradiance variability models supplement the measurement record by extrapolating the observations to broader spectral range and longer time periods than directly observed. Version 1 of the NASA-NOAA-LASP (NNL) solar irradiance variability models are observation-based models that prescribe change in TSI and SSI based on change in solar magnetic activity features called faculae, that enhance solar irradiance at most wavelengths, and sunspots that reduce solar irradiance.

Earth's clouds are critical for weather and climate. Cloud formation in earth and other planetary atmospheres is a deceptively simple physical process of condensation. And yet clouds are very challenging to understand and predict due to the interplay of clouds with their environment. Cloud physics spans 12 orders of magnitude in space from the micro-scale of cloud drops to the planetary scale of the general circulation and a similar order of magnitude in time from fractions of a second of cloud drop collisions to centennial climate time scales.

The remarkable precision of optical atomic clocks enables new applications and can provide sensitivity to novel and exotic physics. In this talk I will explain the motivation and operating principles of a “multiplexed" strontium optical lattice clock, which consists of two or more atomic ensembles of trapped, ultra-cold strontium in one vacuum chamber. This miniature clock network enables us to bypass the primary limitations to standard comparisons between atomic clocks and thereby achieve new levels of precision.

Hypothesized in the 1960s with the first evidence in the 1990s, the origin, quantity, and distribution of water on the Moon – and other airless bodies – is one of the most exciting questions in planetary sciences. Where did it come from? How much is there? What processes at what rates control the modern day distribution? And where *exactly* is the water? Fine-scale spatial knowledge of distribution is needed so that we can send landed missions to measure and sample for textures, elements, the presence of other volatiles, and isotopes to answer the questions above.