Past Events

Linear spectroscopy is used to learn about transitions from the ground states of systems. Nonlinear spectroscopies, such as transient absorption (TA) spectroscopy, first excite the system and then probe after some time delay, giving dynamical information about excited states and spectral information about their excitations. If the pump pulses are strong enough, then some molecules are excited multiple times, and the signal has contributions from singly excited molecules mixed with those from multiply excited molecules.

NASA science missions are often complex systems of systems, involving various stakeholders, including the United States’ Congress. To ensure a clear and concise communication of expectations, requirements, and constraints, NASA has adopted the Science Traceability Matrix (STM). STM provides a logical flow from the decadal survey to science goals and objectives, mission and instrument requirements, and data products. STM serves as a summary of what science will be achieved and how it will be achieved, with a clear definition of what mission success will look like.

Atomic electron tomography (AET) enables the determination of 3D atomic structures by acquiring a sequence of 2D TEM projection measurements of a particle and then computationally solving for its underlying 3D representation. AET is a challenging and labor-intensive experiment! In this talk, we offer two computational methods to alleviate these challenges and make the reconstruction procedure more robust.

Abstract: A new zoo consisting of dozens of heavy subatomic particles that contain more than three quarks and antiquarks have been discovered beginning in 2003.  Although they must be described by the fundamental quantum field theory QCD, the pattern of these exotic heavy hadrons remained unexplained for more than 20 years.  I will present a simple proposal for the pattern based on the Born-Oppenheimer approximation for QCD.  There are simple calculations in lattice QCD that would corroborate the pattern.

The quantum 2.0 revolution is well underway, with a tantalizing future just over the horizon wherein computing, networking, sensing, and even time-keeping will be unimaginably more capable than they are today. The promise of this future hinges on the ability to control, entangle, and measure both individual qubits and large systems of them. Many of the most promising physical qubit systems being developed for these purposes are atomic in nature, i.e. trapped neutral atoms, trapped ions, and artificial atoms in crystals.

A surprising discovery has been compact systems of Earth to super- Earth-sized planets. While compact systems are common, their origin is debated. A prevalent assumption is that compact systems formed after the infall of gas and solids to the circumstellar disk ended. However, observational evidence suggests accretion may commence earlier. We propose that compact systems are surviving remnants of planet accretion during the end stages of infall.

Abstract: In recent years, neutral atom tweezer arrays have emerged as a promising platform for quantum computing. Among various atomic species, alkaline-earth(-like) atoms—particularly ytterbium—offer unique advantages arising from their rich internal structure. In this talk, I will present progress from my PhD work, demonstrating how these features can be harnessed to build a useful quantum computer in the future.

The year 2024 was a breakthrough year towards the development of a nuclear optical clock, with three experiments reporting success in the laser spectroscopy of the lowest nuclear excited state of 229-Th. The highest accuracy was achieved at JILA via direct frequency comb spectroscopy of this, previously elusive, nuclear state. This success is the result of several decades of effort to precisely determine the transition energy and a first step towards nuclear precision spectroscopy and the development of a nuclear frequency standard of extremely high accuracy.

Engineering heterogenous multicellular tissue with native complexity remains one of the holy grails of regenerative medicine and basic biological research. As success in this regard would yield powerful bioengineered constructs useful in functional transplantation, high-throughput drug screening, and fundamental biology investigation, research efforts in our lab have centered around developing and implementing tools to spatiotemporally customize living cell function both from the “outside–in” and from the “inside–out”.

Over the last 20 years, we have discovered that we live in a molecular Universe: A Universe with a rich and varied organic inventory; A Universe where molecules are abundant and widespread; A Universe where molecules play a central role in key processes that dominate the structure and evolution of galaxies. A Universe where molecules provide convenient thermometers and barometers to probe local physical conditions.

Abstract: The discovery of thousands of planets orbiting stars beyond the solar system has fundamentally shifted our view of Earth’s place in the Universe, has captivated the public imagination, and has transformed research priorities in astrophysics. We are now actively searching for atmospheres on temperate, terrestrial planets, and are developing the technical tools to find and characterize “Earth-2.0”.

The behavior of the doped Hubbard model at low temperatures is a central problem in modern condensed matter physics, with relevance to correlated materials such as cuprate superconductors. Despite extensive computational studies, many open questions remain on its low-temperature phase diagram, motivating its study through quantum simulation with ultracold fermionic atoms in optical lattices. Here, leveraging a recent several-fold reduction in experimental temperatures, we report the first direct experimental observation of the pseudogap metal in the Hubbard model.

Join us on Saturday, November 15, 2025, for an electrifying experience as CU Physics Professor Daniel Bolton uncovers the wonders of electric charges and magnets up close! Ever wondered how electrical attraction and repulsion function or what transpires inside an electric circuit? Curious about the inner workings of a power plant in generating electricity? 

Abstract: Modeling gas-phase chemical kinetics relevant to combustion and atmospheric chemistry requires a complete description of elementary reactions involving ephemeral species such as hydroperoxyalkyl radicals, Q̇OOH, which undergo competing sets of unimolecular reactions and bimolecular reactions with O2. The balance of flux from the competition affects rates of chain-branching and inherently depends on temperature, pressure, and oxygen concentration.

In this workshop, you will learn how to tailor your research for different audiences. It will provide you with skills to present your work for job interviews in academia and industry. You will also learn how to apply these communication skills to the public and have the opportunity to practice with feedback from trained experts in science communication. All JILAns are welcome to attend.

The workshop is two hours total and will be offered twice: 
Option 1: Wednesday November 12, 10am-12pm in JILA X325
Option 2: Thursday November 13, 2-4pm in JILA X317

The study of atmospheric escape from exoplanets has undergone significant advances in the recent decade.

Abstract: Ultrafast infrared spectroscopy in its extension to nano-imaging provides access to vibrational and low energy carrier dynamics in molecular, semiconductor, quantum, or polaritonic materials. In addition, to simultaneously probe both ground and excited state dynamics we have developed ultrafast heterodyne pump-probe nano-imaging with far-from-equilibrium excitation.

Abstract: Understanding thermal transport and light-matter interactions at the extreme scales is both fundamentally important and practically relevant. Studying these regimes often demand new instrumentation and high-resolution sensing techniques. In this talk, I will present my lab’s efforts to explore the complex landscape of heat transport and nanophotonics at the atomic and single-molecule scale. Specifically, we have developed microfabricated scanning thermal microscopes with picowatt- and sub-picowatt sensitivity and atomic spatial resolution.

The Department of Biochemistry invites professors and scientists fr