The understanding of strongly-correlated quantum matter has challenged physicists for decades. Such difficulties have stimulated new research paradigms, such as ultra-cold atom lattices for simulating quantum materials. In this talk I will present a new platform to investigate strongly correlated physics, based on graphene moiré superlattices. In particular, I will show that when two graphene sheets are twisted by an angle close to the theoretically predicted ‘magic angle’, the resulting flat band structure near the Dirac point gives rise to a strongly-correlated electronic system.
Duane Physics Room G1B31
The quantum theory of magnetism has provided many durable paradigms for quantum phases of matter, including intrinsically quantum disordered states, symmetry-protected topological phases, and quantum spin liquids. In this lecture, I will review some of the history and highlights of this very rich field.
The program to search for dark matter in the past couple of decades has mostly focused on the WIMP (weakly interacting massive particle) at the GeV - TeV scale. It has made impressive strides in sensitivity but has yet to unearth the particle nature of dark matter. Recently there have been many new initiatives to broaden the search for dark matter, many of them smaller scale experiments.
Physics Education Research is both about improving instruction and understanding the fundamentals of what learning is and how learning manifests in its many forms. In this talk I describe the development of Modeling Instruction (MI) for University Physics as a research endeavor into improving instruction. Modeling is built on the idea that all science proceeds through an iterative process of model development, evaluation, deployment, and revision. Accordingly, effective science instruction should promote the development of modeling skills by engaging students in the practices of modeling.
The quantum wavefunction presents the ultimate "big data" problem in physics. When many quantum particles interact in a low-temperature material or a quantum computer, the complexity of the quantum state presents a daunting challenge for any classical simulation strategy. Recently, a new computational toolbox based on modern machine learning techniques has been rapidly adopted into the field of condensed matter and quantum information physics.
We live at a time of contradictory messages about how successfully we understand gravity. General Relativity seems to work very well in the Earth’s immediate neighbourhood, but arguments abound that it needs modification at very small and/or very large distances. This talk tries to put this discussion into the broader context of similar situations in other areas of physics, and summarizes some of the lessons which our good understanding of gravity in the solar system has for proponents for its modification over very long and very short distances.
X-ray sources from laser-plasma acceleration: development and applications for high energy density sciences
Bright sources of x-rays, such as synchrotrons and x-ray free electron lasers (XFEL) are transformational tools for many fields of science. They are used for biology, material science, medicine, or industry. Such sources rely on conventional particle accelerators, where electrons are accelerated to gigaelectronvolts (GeV) energies. The accelerating particles are also wiggled in magnetic structures to emit x-ray radiation that is commonly used for molecular crystallography, fluorescence studies, chemical analysis, medical imaging, and many other applications.
Van der Waals heterostructures are constructed by layering atomically thin crystals such as graphene, with interlayer bonding provided by the van der Waals force.
The solar wind and its embedded magnetic field flow outward from the sun in all directions, inflating a bubble in the local interstellar medium called the heliosphere. Prior to 2004, there were very few direct observations of the interaction of the heliosphere and local interstellar medium and our knowledge of these regions was largely theoretical. Then, 2004 and 2007 the Voyager 1 and 2 spacecraft crossed the heliosphere’s termination shock and in 2012 and 2018, each went on to cross the heliopause and entered interstellar space.