In this talk, I will discuss two recent developments centered on the physics and manipulation of hyperfine interactions in atomic and molecular systems. First, I will introduce an all-optical method for performing qudit gate operations in alkaline-earth and alkaline-earth-like atoms. Our scheme utilizes single-beam Raman transitions within the 1S0 to 3P1 manifold to achieve coherent manipulation of high-dimensional hyperfine levels, compatible with non-destructive readout and two-qudit gates via Rydberg blockade.

Second, I will shift to the molecular domain to explore the coupling between magnetism and atomic or molecular motion. This topic has seen a recent surge of interest due to the study of chiral phonons in solid state systems. Using modern ab initio methods and analytic models, we conduct a theoretically rigorous investigation of vibrational molecular magnetism, re-visiting this long-standing problem to derive relevant coupling parameters for spin-vibration interactions and predict localized, vibrationally induced magnetic fields.

Wildfires are becoming increasingly frequent and intense in a warming climate, reversing decades of air quality improvements, as seen in the 2025 Los Angeles Fires and many other record-breaking events worldwide. Crucially, what burns locally doesn’t stay local—wildfire smoke often rises, travels, and affects the atmosphere and climate far beyond its source. I will share new insights into the far-reaching impacts of wildfire smoke based on aircraft measurements, satellite observations, and modeling. At the regional scale, I will present first-of-its-kind aircraft sampling of wildfire smoke at ~14.5 km altitude, revealing unexpectedly large aerosol particles that enhance outgoing radiation by ~35%, challenging conventional model assumptions. Next, I will show how high-altitude wildfire smoke perturbs Earth’s energy balance and global temperatures, with the 2019/20 Australian wildfires leaving detectable climate fingerprints in the atmosphere comparable to major volcanic eruptions, and causing the strongest stratospheric warming of this century. I will conclude with future perspectives on bridging measurements and modeling to advance understanding of aerosol-chemistry-climate interactions in a world increasingly shaped by wildfires and shifting anthropogenic emissions.

Partnerships for Informal Science Education in the Community (PISEC) is the longstanding JILA-PFC community partnership-based public engagement program. PISEC connects university volunteers with K12 youth to engage in hands-on, inquiry-based science activities and projects through afterschool clubs and in-class project-based mentorship. We seek to support youth STEM identity development and to cultivate and sustain students' interest in STEM by co-creating transformative and empowering experiences with STEM. Simultaneously, we offer valuable teaching, science communication, and leadership experience for the university participants. In this talk, we will discuss the details of the PISEC program and provide an overview of past and ongoing education research studies on various aspects of the program. We will also have a chance to engage in fun, hands-on activities! We invite all JILAns to attend, whether you have participated in PISEC before or are hearing about it for the first time. Join us to get a taste of JILA-PFC public engagement and learn about opportunities to get involved.

Active systems are driven out of equilibrium by exchanging energy and momentum with their environment. This endows them with anomalous mechanical properties which leads to rich phenomena when active fluids are in contact with boundaries, inclusions, or disordered potentials. Indeed, studies of the mechanical pressure of active fluids and of the dynamics of passive tracers have shown that active systems impact their environment in non-trivial ways, for example, by propelling and rotating anisotropic inclusions. Conversely, the long-ranged density and current modulations induced by localized obstacles show how the environment can have a far-reaching impact on active fluids. This is best exemplified by the propensity of bulk and boundary disorder to destroy bulk phase separation in active matter, showing active systems to be much more sensitive to their surroundings than passive ones.

Strain is powerful for discovery and manipulation of new phases of matter; however, elastic strains accessible to epitaxial films and bulk crystals are typically limited to small, uniform, and discrete values. In this talk I will describe our progress on synthesizing single crystalline membranes of Heusler compounds, which enable large continuously tunable strains and strain gradients via bending and rippling. This synthesis strategy borrows ideas from remote epitaxy and van der Waals epitaxy on graphene, and I will describe our current understanding of the growth mechanisms. I will then show how strain gradients transform rippled GdPtSb membranes from an antiferromagnet to a room temperature ferromagnet via flexomagnetic coupling, and how larger strain gradients induce flexomagnetism [5] and superconductivity in GdAuGe membranes. Finally, I will discuss new efforts on tuning ultrafast magnetism in membranes via combined strain and optical excitation. Our strained Heusler membranes offer a highly tunable platform for discovery of new topological, magnetic, and superconducting phases both in and out of equilibrium.

In this seminar, I present recent results on the structure, variability and energetics of the far upper atmosphere found by the method of solar occultation, where atmospheric properties are inferred using sunlight as it passes through an atmosphere. The extreme ultraviolet (EUV) band is strongly absorbed in the thermosphere, enabling EUV occultations to provide a unique window into a sparsely observed region of the atmosphere. I begin with new findings that clearly distinguish the roles of Mars’s large orbital eccentricity and the Sun’s 11-year solar cycle in driving the climatology of Mars’s thermosphere. I then turn my attention to Earth, where I show EUV occultations can be used to help improve a long-standing miscounting of the EUV energy input to the thermosphere as well as for quantifying energy dissipated by gravity waves in the thermosphere. Finally, I show results found using solar occultations at the 121.6 nm H Lyman-alpha transition to measure the variability of the inner geocorona, which has been inaccessible to past remote sensing techniques. Students have been a major contributor to these results and their participation is highlighted. This presentation also features future missions, including the upcoming Occultation Wave Limb Sounder (OWLS) mission, of which I am Principal Investigator (PI), planned for launch in early 2027 to measure the relation between gravity wave energy and thermospheric temperature, as well as a NASA-funded vacuum ultraviolet Fourier Transform Spectrometer technology development program, of which I’m also PI, intended for the Earth Coronal Hot Hydrogen Observatory (ECHHO) mission to measure the energetics of the geocorona.

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.

For the last quarter century, experiments at Brookhaven National Laboratory’s  Relativistic Heavy Ion Collider and the LHC at CERN have measured extremely high-energy heavy-ion collisions with the hope of producing the Quark Gluon Plasma (QGP) and extracting its properties. The success of this mission depends critically on combining careful, detailed and thorough measurement with complex multi-component theoretical simulations. I will first review how specific bulk properties are illuminated by specific experimental observables. I will then show how the comparison of these large heterogeneous data sets with computationally expensive models built on high-dimensional model-parameter spaces are rigorously constraining these properties through state-of-the-art Bayesian analysis. The extracted equation of state and chemical compositions are found to be consistent with lattice gauge theory. Other properties, which are not so well calculated on the lattice, such as the opacity and emissivity of QCD radiation, the diffusivity of both light and heavy quarks, and the viscosities have also been extracted. I will review where these determinations currently stand and how well they substantiate the claim of having produced the QGP in the laboratory. 

Join alumni and faculty from the Astrophysical & Planetary Sciences and Physics departments as they share their experiences and advice on applying for jobs, careers in quantum, and careers in heliophysics!

The dynamics of Earth’s radiation belts remain one of the central challenges in space weather research. Despite decades of satellite observations, predicting when and how the belts will intensify or decay remains difficult. This seminar will discuss recent work combining multi-mission datasets from 36 multi-agency satellites to produce the highest-resolution phase space density (PSD) observations of the outer belt to date, and how these have been used to identify dominant acceleration and loss mechanisms. New developments in data-assimilative modelling through the Radiation Belt Forecasting Model and Framework (RBFMF) will also be discussed, including how diminishing real-time data coverage affects operational hindcasts. The results highlight the need for continuous, strategically placed measurements through the heart of the radiation belts and improved understanding of which orbital configurations most effectively enhance prediction capability.

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.

As educators, we would like to prepare our students for 21st century physics careers. Overall, to ensure all students will become successful scientists, physics departments need to be able to provide evidence to make sure that we are reaching these goals. The field of Physics Education Research has made major contributions to various educational practices and materials to reform instruction in order to recruit and retain more students. However, while many research-based instructional strategies in physics have continued to advance, reform in undergraduate physics assessment tools has had limited space in these conversations. In this talk, I will motivate the need for the next generation of physics assessment tools and present a few projects that my physics education research lab at Michigan State University has been working on. In particular, I will discuss our efforts to build a more diverse set of tools to use within our classrooms in order to better understand our students’ learning as well as how we can best support them throughout their time in higher education.

Explore physics and quantum-related research through student showcases and poster sessions. Hear from industry executives Safy Fishov (AMD) and Billy Landuyt (ExxonMobil), and network with engineers from AMD. Food will be provided!

Visit the Research Expo website to RSVP or Register to present a poster:

• Register to present a poster by March 22.
• RSVP to attend by April 3.

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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 first year of a Ph.D. is our last opportunity to gather students heading into every research area and tell them one long-form story. Because they have just finished an undergrad degree, it is also our first opportunity to focus on the interconnections that make us so happy doing physics, to break out of the silos bounding undergrad courses. Also, many aspects of Physics culture can at last be expressed in concrete form, including symmetry/geometry as the drivers of physical insight. I'll offer an approach that focuses on crazy phenomena that make us ask, "How could anything like that possibly happen at all?" After so much education, students are sometimes shocked at how many such questions remain; some are delighted by how many of them are tractable with ideas that are in their heads, but not fully interconnected yet.

This century is witnessing a second quantum revolution, and quantum sensing represents an area in which chemists can make significant contributions. Achieving quantum sensing requires more than precise control of quantum states at the molecular level; it is also crucial to organize molecular qubits so that they function effectively in complex environments. In this seminar, I will discuss materials chemistry approaches to molecular quantum sensors, focusing on their extension from biological systems to engineered materials.
We have recently enabled intracellular quantum sensing by developing molecular quantum nanosensors (MQNs). By encapsulating atomically optimized molecular spin qubits within biocompatible nanocrystals, MQNs achieve highly uniform spin energy levels and enable room-temperature optical detection of molecular spin states inside living cells. Compared with existing quantum sensors, MQNs exhibit superior uniformity, making absolute temperature sensing within cells possible—an achievement that has been challenging to realize with conventional platforms.
I will then show how molecular quantum sensing can be extended into chemically programmable materials. By incorporating photoactive chromophores as components of metal–organic frameworks (MOFs), these MOFs enable spatial organization and chemical accessibility of molecular qubits. This design allows quantum sensors whose spin coherence times respond to surrounding chemical species at room temperature. Finally, I will discuss how controlled molecular assembly leads to multilevel quantum states (qudits). Through precise chromophore arrangement, singlet fission generates spin-correlated quintet triplet pairs with submicrosecond quantum coherence, expanding molecular quantum sensing beyond two-level systems. Together, these examples illustrate how materials chemistry transforms molecular qubits from isolated spin systems into versatile sensing platforms that function across biological and materials environments.

The Will Lab studies quantum systems of ultracold atoms and molecules. The lab cools atoms and molecules to temperatures less than a millionth of a degree above absolute zero, where atomic behavior is fully governed by quantum mechanics. Under these conditions, the lab controls individual quantum particles and their interactions with high precision using atomic physics tools, enabling novel platforms for many-body quantum physics, quantum simulation, quantum computing, and quantum optics. Their work spans from fundamental physics—including the first molecular Bose–Einstein condensates—to applied quantum technologies such as large-scale atomic tweezer arrays, opening new approaches to quantum information science and quantum networking.

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.

Condensed matter physics aims to explore and understand various quantum phenomena that emerge from the interactions between nuclei and electrons. Through synthesizing and investigating various crystals, this constructionism approach has led to the discovery of many amazing phenomena, especially when the principles of electron correlation and topology play important roles. The settings of such conventional crystals are often very complicated, making it hard to extract the essential ingredients and understand the underlying physics. In this talk, I will show our efforts on establishing a new paradigm, based on a material known as rhombohedral graphene, which is part of natural graphite. Rhombohedral graphene has the simplest chemistry and structure, yet can be controlled by a set of experimental knobs to exhibit many intriguing phenomena in condensed matter physics. Beyond phenomena that were familiar, I will focus on two newly observed quantum phases of matter, chiral superconductor and fractional quantum anomalous Hall effect. I will show their construction, phenomena, and implications for quantum many-body physics and applications. In the end, I will discuss new opportunities to be explored in this new paradigm.

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.

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.

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