Kiosk 2

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. These examples include measurements of the polarization of light from circumstellar matter and exoplanets; aerosol measurements in Earth’s atmosphere; detection of signs of homochirality associated with life; adaptive optics, coronagraphs, and control algorithms for exoplanet characterization; and biomedical applications. I will also discuss some unexpected insights into the reflection of light by optical elements and will conclude by looking ahead to a future where filters and spectrographs may become obsolete.

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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.   I will discuss how correlated dissipation and structured environments can induce synchronization between quantum degrees of freedom that do not synchronize in isolation. Using simple but physically motivated models—ranging from coupled qubits and oscillators to excitonic and polaritonic systems—I will show how environmental correlations reshape the system’s dynamical symmetry, protect specific collective modes, and lead to robust phase locking even in the presence of strong decoherence. A central theme will be the role of symmetry and mode structure: by transforming to collective coordinates, one finds that noise correlations can selectively suppress dissipation in certain subspaces while enhancing it in others, effectively stabilizing synchronized quantum motion. I will also discuss how these effects manifest in experimentally accessible observables, including coherence measures, spectral responses, and photon correlations, and how they connect to recent ideas from open quantum systems, exceptional points, and quantum information theory.   Beyond its conceptual interest, noise-induced quantum synchronization offers a new route to controlling coherence in realistic, dissipative platforms, with implications for quantum sensing, molecular photonics, and engineered quantum materials. 

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. I will discuss how the investigation of magnetic star-satellite interactions is opening new possibilities to study the space weather environments around different kinds of stars.  New ground-based radio facilities coming online in the near-term will revolutionize this field, enabling new science connections between ground and space-based observatories, and modeling initiatives. Understanding the physics of star-satellite interactions now is a LASP science opportunity, and will pave the way in the coming decades toward maximizing the science potential of future missions with a focus on characterizing habitable exoplanets.

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 new spin-vibronic interaction represents a non-Abelian Berry curvature on the ground-state electronic manifold and generates an effective magnetic field for the ground-state electronic spin dynamics. We further develop a spin relaxation rate theory that estimates the spin relaxation time via the two-phonon Raman process and the molecular crystal vibrational dynamics. The application of the dynamic molecular spin Hamiltonian to S=1/2 molecular qubits demonstrates that the spin relaxation time at elevated temperatures is dominated by the non-adiabatic spin-vibronic interaction. The computed spin relaxation rate and its magnetic field orientation dependence are in agreement with experimental measurements. Analysis of the influence of the molecular electronic structure on the strength of the spin-vibronic interaction charts new avenues for the improvement of the spin-coherent properties of molecular systems.

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. In addition to observing quantum interference in atom-exchange reactions [Science 384, 1117 (2024)], we hope to shed light on the puzzle of reaction complexes that live 5 orders of magnitude longer than expected.

For the overwhelming majority of organisms, effective communication and coordination are critical in the quest to survive and reproduce. A better understanding of these processes can benefit from physics, mathematics, and computer science – via the application of concepts like energetic cost, compression (minimization of bits to represent information), and detectability (high signal-to-noise-ratio). My lab's goal is to formulate and test phenomenological theories about natural signal design principles and their emergent spatiotemporal patterns. To that end, we adopted insect swarms as a model system for identifying how organisms harness the dynamics of communication signals, perform spatiotemporal integration of these signals, and propagate those signals to neighboring organisms. In this talk, I will focus on two types of communication in insect swarms: visual communication, in which fireflies communicate over long distances using light signals, and chemical communication, in which bees serve as signal amplifiers to propagate pheromone-based information about the queen's location. Through a combination of behavioral assays and computational techniques, we develop and test model-driven hypotheses to gain a deeper understanding of these communication processes and contribute to the broader understanding of animal communication.

CU Physics Prof. James Thompson explains how superheroes' understanding of fundamental physics ensures truth and thwarts villains! Sparks, explosions and plenty of action will punctuate this free STEM show that's open to students of all ages.

For over 40 years, CU Wizards presents FREE STEM Saturday morning shows for kids and their families. Visit: www.colorado.edu/cuwizards

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. 

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I will discuss the standards of time and frequency and how these standards have evolved over the centuries. I will present the current definitions of time and frequency and how these definitions are likely to evolve in the coming years.

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