Nuclei make up 99% of the mass in the visible universe, and all but the lightest nuclei are produced in cataclysmic stellar events such as supernova explosions and neutron star mergers. Every proton (and neutron) within all nuclei is governed by QCD, the theory of quarks, gluons, and their interactions. Understanding the amazing world inside a proton requires tremendous technical capabilities embodied in large accelerator facilities and advanced detector technology, as found at the world-class facilities of Jefferson Laboratory. These capabilities enable us to understand how QCD supports the dynamical generation of bound states with a rich variety as seen from data. Interestingly, the more closely one peers into a proton (with higher-energy electrons), the more complex the emergent phenomena one measures. Tying these measurements to theory often requires models informed by LQCD calculations. Furthermore, JLab’s experimental capabilities, using parity violation, have recently enabled a precise measurement of the thickness of the neutron skin in Pb which has implications in the astrophysics associated with neutron-star mergers. This interplay is but one demonstration of how the world of the small, even at the proton level, affects the most violent of collisions in the universe.

Non-zero neutrino masses provide the strongest evidence for physics beyond the Standard Model of particle physics. Large neutrino detectors and cosmological observations provide more and more information about neutrino masses and mixing angles, and might soon converge toward a self-consistent description with precisely measured parameters. The origin of neutrino masses remains mysterious, however, with a seemingly unlimited number of possible models flooding the literature. I will discuss ways to potentially distinguish certain classes of models and how to render a neutrino-mass theory predictive by connecting it to other anomalous observables such as the muon’s magnetic moment or CDF’s W-boson mass.

In order for artificial neural networks to learn a task, one must solve an inverse design problem. What are all the node weights for the network that will give the desired output? The method by which this problem is solved by computer scientists can be harnessed to solve inverse design problems in soft matter. I will discuss how we have used such approaches to design mechanical and flow networks that can perform functions inspired by biology. I will also show how we can exploit physics to go beyond artificial neural networks by using local rules rather than global gradient descent approaches to learn in a distributed way.

Understanding chirality, the intrinsic handedness of a system, is important for future technologies using quantum magnetic materials.  Of particular interest are magnetic skyrmions which are chiral and topologically protected, meaning that their spin textures can act as barriers from deformation in crystalline grains.  However, most electron microscopy studies use Lorentz TEM or holography to investigate chirality in skyrmions in nearly perfect single crystals because Fresnel effects may cause signals from grain structures to be mistaken as magnetism when the two are comparable in size.  In this work, we probe nanomagnetism of topological magnetic textures in sputtered thin film of B20 FeGe on Si to study the relationship between magnetic and crystal chirality.  Using 4D-STEM, we find that the vorticity and helicity of these magnetic topological phases are coupled to the crystal chirality.  Furthermore, our work shows that signals from magnetism can be disentangled from crystalline effects for sub-micron grains, enabling a new way to investigate topological magnetism in the presence of small polycrystalline grains. This methodology is important for spintronics and low-power magnetic memory technologies that rely on scalable techniques for large scale manufacturing of real devices. 

Our solar system is embedded in the Local Bubble, an expanding, 1,000-light-year-wide cavity in the interstellar medium (ISM).  The Bubble was created ~14 million years ago by a chain of supernova explosions that drove out most of the diffuse dust and gas in the nearby ISM.  Recent work mapping the 3D shape and dynamics of the Local Bubble has revealed that nearly all recent star formation within
200 pc of the Sun was triggered by the Bubble's rapid expansion.  The exact mechanics of this expansion, and the role that magnetic fields in the ISM have played in regulating its evolution, is not yet clear.  By combining detailed models of the Bubble’s geometry (derived from 3D dust
mapping) with Planck dust polarization observations and the assumption that magnetic field vectors are tangent to the Bubble’s surface, we are able to infer the Bubble’s 3D magnetic field orientation.  This map is the first to fully chart magnetic fields over an observed superbubble in 3D.  We analyze the relationship between the Local Bubble’s magnetic field and background starlight polarimetry observations, and discuss how magnetic fields may have affected the dynamics of the Local Bubble and progression of nearby star formation.

Using muon tomography, the Non-invasive Archaeometry Using Muons (NAUM) Project will image the interiors of ancient Maya temples in Chichén Itzá, Mexico to uncover their unknown internal structures.
Conceptually, muon tomography is the nascent science of collecting muon flux measurements through cross sections of an object to graphically visualize the internal massive structure. NAUM’s volumes of interest lie beneath the multi-stacked Maya temples at Chichén Itzá. The Maya city of Chichén Itzá, on the Yucatan Peninsula in Mexico, was a regional capital housing a great deal of historical and cultural significance for the Maya people. By imaging the Temple of Kukulcán with muon tomography, we can non-invasively explore inside this monumental structure while preserving its history and glean information on how and why the scientifically and mathematically intelligent Maya civilization built these great landmarks. This presentation describes the project's history, process, and progress, including results from a trip to Chichén Itzá, muon flux simulations, prototype detector fabrication and testing at the Fermilab Test Beam, and the prototype's resolution analysis.

Dark matter is believed to make up most of the matter in our Universe, but its particle origin remains a mystery.  A favorite candidate is the so-called Weakly Interacting Massive Particle (WIMP), but a diverse set of experiments are rapidly closing the available parameter space for WIMPs.  I will show that small changes to the assumptions about how dark matter was produced in the early Universe lead to very different dark matter masses and interaction strengths.  I will chart ``phase diagrams” for the production of dark matter with a thermal or non-thermal origin.  I will explain how different phases of dark matter production map onto different experimental prospects.

Combining low-dimensional correlated condensed matter systems with judiciously placed and optically accessible quantum impurities is a fruitful enterprise for (1) diverse sensing modalities of fundamental equilibrium and transport properties in a variety of systems, (2) designing and building up quantum-entangled dynamics of the quantum bit ensembles, and (3) using such dynamics to imprint measurable quantum correlations back onto the condensed matter systems and devices. This interplay between macroscopically controlled solid-state heterostructures and intricate highly-correlated quantum dynamics of atomistic quantum degrees of freedom opens up a rich and versatile playground for fusing ideas from quantum optics, quantum transport, and quantum material sensing and engineering. I will summarize our current ideas, focusing on the overarching symmetry and nonequilibrium thermodynamics based reasoning.

 

Thermodynamics provides a robust conceptual framework and set of laws that govern the exchange of energy and matter. Although these laws were originally articulated for macroscopic objects, nanoscale systems also exhibit “thermodynamic­-like” behavior – for instance, biomolecular motors convert chemical fuel into mechanical work, and single molecules exhibit hysteresis when manipulated using optical tweezers. To what extent can the laws of thermodynamics be scaled down to apply to individual microscopic systems, and what new features emerge at the nanoscale? I will describe some of the challenges and recent progress – both theoretical and experimental – associated with addressing these questions.  Along the way, my talk will touch on non-equilibrium fluctuations, “violations” of the second law, the thermodynamic arrow of time, nanoscale feedback control, strong system-environment coupling, and quantum thermodynamics.

Quantum computing and simulation promise to revolutionize fundamental physics, technology, and quantum chemistry. Simulating quantum systems using analog platforms was first proposed in the 1980s, but recent technological advances have brought this idea to new heights. Trapped atoms and ions, superconducting circuits, and advanced solid-state platforms have achieved an unprecedented level of quantum control and are able to model increasingly complex Hamiltonians. Quantum simulation in 2D solid platforms has proved to be incredibly versatile, while also being compatible with the existing semiconductor technology. In this colloquium, I will showcase the exciting recent developments in the field of 2D quantum simulators, highlighting twisted moiré systems and atomic manipulation. Scanning tunneling microscopy (STM) has proved crucial for the progress of this field. My focus will be on revealing the topological and strongly correlated physics in twisted layered graphene and on the surprising insights gained through the use of STM. Through high-resolution magnetic field scanning tunneling spectroscopy, we have demonstrated the importance of the fine details of quantum geometry in these novel 2D platforms. Specifically, I will report on the discovery of an emergent anomalously large orbital magnetic susceptibility in twisted double bilayer graphene, along with the orbital magnetic moment. I will also discuss the exciting future potential in the field of quantum materials, combining STM, epitaxial growth, and stacked 2D devices.

Entanglement is the strangest feature of quantum theory, often dubbed ''spooky action at a distance’’. Quantum entanglement can occur on a macroscopic scale with trillions of electrons, leading to "strange metals" and novel superconductors which can conduct electricity without resistance even at relatively high temperatures. Remarkably, related entanglement structures arise across the horizon of a black hole, and give rise to Hawking’s quantum paradox. This lecture will be designed to introduce these forefront topics in current physics research to a general audience.

Quantum information is a rapidly growing field that continues to develop and explore a variety of platforms to realize scalable quantum devices. Progress in qubit technology is driven by continued advancement in materials research, which informs fundamental issues such as the underlying mechanisms limiting qubit coherence times. Further, quantum materials including superconductors, magnets, insulators, and topological materials all offer unique properties that can be implemented into quantum circuits to realize new functionalities. In this way, the fundamental physics of quantum materials is intertwined with the development of next-generation quantum devices.
In this talk, I will discuss several topics at the intersection of quantum information and quantum materials research, which demonstrate this symbiotic relationship between the two fields. This includes how one can use Josephson junctions - a critical element of the Transmon qubit - formed into arrays to serve as both a quantum simulator of interacting many-body systems such as the Hubbard model as well as a novel platform to study quantum phase transitions such as the superconductor-to-insulator transition. Additionally, I will discuss how microwave circuits can be used as a sensitive probe of the order parameter symmetry in low-dimensional unconventional superconductors and mesoscopic heterostructures, as well as for a variety of other quantum sensing applications. Finally, I will discuss future opportunities to leverage the interplay between quantum materials and quantum information to both gain insight into enigmatic phases of matter and design novel qubits and quantum devices. 

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The nature of the dark matter in the Universe is among the longest and most important outstanding problems in all of modern physics. The ordinary atoms that make up the known universe, from our bodies and the air we breathe to the planets and stars, constitute only 5% of all matter and energy in the cosmos. The remaining 95% is made up of a recipe of 25% dark matter and 70% dark energy, both nonluminous components whose nature remains a mystery.  I’ll begin by discussing the evidence that dark matter is the bulk of the mass in the Universe, and then turn to the hunt to understand its nature.  Leading candidates are fundamental particles including Weakly Interacting Massive Particles (WIMPs), axions, sterile neutrinos, as well as primordial black holes.  I will discuss multiple experimental searches:  at CERN in Geneva; in underground laboratories; with space telescopes; with gravitational wave detectors; and even with DNA.  I’ll tell you about our novel idea of Dark Stars, early stars powered by dark matter heating, and the possibility that the James Webb Space Telescope could find them.  At the end of the talk, I'll turn to dark energy and its effect on the future of the Universe.

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