Past Events

Abstract: Polaritons are hybrid light-matter states with unusual properties that arise from strong interactions between a molecular ensemble and the confined electromagnetic field of an optical cavity. Cavity-coupled molecules appear to demonstrate energetics, reactivity, and photophysics distinct from their free-space counterparts, but the mechanisms and scope of these phenomena remain open questions. I will discuss new experimental platforms that the Weichman Lab is developing to investigate molecular reaction dynamics under strong cavity coupling.

Abstract: Magnetism is the posterchild of how the interplay between electron-electron interactions and quantum physics promotes novel macroscopic phenomena. Historically, the evolution of our understanding of magnetism has been related to the discovery of new paradigms in condensed-matter physics, as exemplified by the connections between antiferromagnetism and Mott insulators, spin glasses and non-ergodic states, and spin liquids and fractionalized excitations.

While photophoresis, or “light-driven motion,” has long explained how aerosol layers remain aloft in the middle atmosphere, practical applications have only recently been gaining attention. Advances in nanofabrication now allow us to build lightweight structures that can propel themselves upward using photophoretic forces alone. These “photophoretic flyers” can sustain flight in near-space (30–100 km altitudes), a region that is too high for aircraft and balloons and too low for satellites.

Abstract: The development of pulsed Electron Spin Resonance (ESR) spectroscopy at microwave frequencies above 100 GHz remains a challenging and costly task, primarily due to the limited output power of modern high-frequency solid-state electronics. Nonetheless, a range of critical scientific problems—such as dynamic nuclear polarization (DNP) enhancement of NMR and quantum computing applications involving electron spins—necessitate spin relaxation measurements at THz frequencies.

Abstract: CryoEM and cryoET enable imaging of biological specimens frozen in vitreous ice, revealing 3D molecular or cellular structures at high resolution and in their native state. However, cryoET is limited by the “missing-wedge” problem due to restricted tilt angles, and cryoEM often suffers from preferred orientation, resulting in uneven sampling of angular views and leaving parts of Fourier space poorly covered.

Abstract: Modern metrology involves a tight integration of sensors with computation. Suppose that a quantum computer were inserted into this pipeline as the first step in receiving and transforming sensor signals, before classical processing. What could be accomplished?  I illustrate the possibilities with three scenarios for which quantum computation may enhance sensing: demodulation of phase shift keyed signals, trajectory discrimination, and RF signal detection.

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 launch and commissioning of the James Webb Space Telescope is ushering in a new era in our understanding of our cosmic origins. Galaxies are a fundamental building block of the universe, yet how they formed has remained enigmatic owing to our inability to observe them at early cosmic times. In just its first three years of operation, JWST has already upended our understanding of galaxy and black hole growth in the early universe.

Abstract: The tiny particles that comprise almost all the mass in our bodies as well as the stars and planets are held together by a force so strong that it is nearly impossible to break away from it. It’s so strong that if you try to break the glue bond, you’ll create anti-matter particles!

Abstract: My talk will highlight new directions in probing semiconductor electrochemistry and reactivity at the single-particle and single-molecule level. I will discuss our recent discovery that the band gap renormalization (BGR) effect in 2D semiconductors strongly dictates their current–voltage behaviorin electrochemical cells, providing a new framework to understand solid-state transistor device performance variability.

Oxford Ionics develops trapped-ion quantum computers.  We are UK headquartered and opened our US office in Boulder last year.  We will present the work we do in Boulder developing our architecture and our future plans to open a lab and  grow the team here.  We will also discuss our recent acquisition by IonQ and what it means for the companies' joint roadmap.

Abstract: An expected consequence of a warming atmosphere is that atmospheric humidity would rise as a result of the dependency of the atmospheric water vapor holding capacity on temperature (the Clausius-Clapeyron relationship).  But this is only true if there is sufficient availability of water to satisfy the rising atmospheric demand.

Abstract: Social bonds live in our biology. To understand the computations that allow our brains to form social bonds, my lab studies monogamous prairie voles. Unlike laboratory mice and rats, these rodents often mate for life, parenting together and defending a shared home. We have found that social information is organized at multiple scales in the brain's reward center—from stable encoding in individual neurons to coordinated ensembles—to enable bond formation.

Many-body localization (MBL) is a many-body quantum phenomenon that fails to thermalize under strong disorder. While experimental work on optical lattice systems suggests the existence of a MBL phase in 2D, there have been challenges regarding its existence in two dimensions. The main challenge of MBL in higher dimensions is an avalanche instability: rare regions of weak disorder can act as a thermal bath, which eventually thermalizes the entire system.

The availability of exascale computing resources has enabled numerical modeling of astrophysical fluid dynamics at unprecedented scale, including studies of MHD turbulence on grids with 10,000^{3} cells, or MHD models of black hole accretion in full GR with radiation transport. Results from a diverse range of applications will be presented, including new insights into the structure of radiation-dominated accretion disks, modeling AGN feedback in elliptical galaxies, and turbulence and cosmic ray transport in the interstellar medium.

Abstract: Proteins operate within an aqueous environment that influences their folding, stability, and activity. Membrane proteins have the added complication of being embedded in lipid bilayers that play an equally critical, yet significantly less understood, role. Much like solvent conditions modulate enzyme kinetics and protein interactions in solution, the lipid composition of the membrane performs regulatory functions for membrane proteins, affecting their organization, conformational dynamics, and catalytic output.

Abstract: Weakened magnetic braking (WMB) was originally proposed in 2016 to explain anomalously rapid rotation in old field stars observed by the Kepler mission. The proximate cause was suggested to be a transition in magnetic morphology from larger to smaller spatial scales. In a series of papers over the past five years, we have collected spectropolarimetric measurements to constrain the large-scale magnetic fields for a sample of stars spanning this transition, including a range of spectral types from late F to early K.

Abstract: The Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves for the first time in 2015. Since then, hundreds more astrophysical observations have been confirmed. To detect these spacetime ripples requires measurement with sub-attometer precision. I will describe the quantum technologies that make such a measurement possible, enabling present and future discoveries.

Host: Ana Maria Rey

How big would Mercury need to be to retain an atmosphere? How close could Venus orbit the Sun before its atmosphere erodes away? Are habitable Earth-like atmospheres even possible around the smallest stars? In this talk, I describe how exoplanet observations are starting to provide insight on what environments permit terrestrial planet atmospheres to thrive.

Quantum metrology enables some of the world's most sensitive measurements with potentially far-reaching applications in the life sciences. Although the ultrahigh sensitivity of qubit sensors has sparked the imagination of researchers, implementing them in actual devices that enable monitoring cellular processes or detecting diseases remains largely elusive. Overcoming the limitations that hinder the broader application of quantum technology in the life sciences requires advances in both fundamental science and engineering.