Events

Title: The Search for Life in our Solar System and Beyond

Abstract: The drive to explore space is at least partly driven by the desire to discover whether life exists beyond the Earth. Exploration of planets and moons in our Solar System began in earnest several decades ago and has continued at a slow, but steady, pace since that time. The most likely venues are subsurface liquid water environments on Mars and on giant planet moons, but even Titan and Venus have caught astrobiologists' interest. The possibility that humans will visit Mars within the next 20 years makes this search even more exciting.

The best chance for actually finding life, however, may be on planets orbiting other stars. Telescopic observations from Hubble, Kepler, and now JWST have shown that exoplanets are abundant and that at least a few of these are potentially habitable. NASA's planned Habitable Worlds Observatory should allow us to find many more such habitable worlds and to search spectroscopically for signs of life, also hopefully within the next 20 years. So, the long-standing question, 'Are we alone?' may soon be answered.

Speaker Bio: James Kasting is an American geoscientist and Distinguished Professor of Geosciences at Penn State University. He is considered a world leader in the field of planetary habitability, assessing habitable zones around stars. He is interested in atmospheric evolution, planetary atmospheres and paleoclimates. Kasting writes about the geophysical history and status of the Earth, with a focus on atmospherics. He was well known among the geologists for his ground breaking idea on the only long term negative feedback for the atmospheric carbon dioxides: the carbon silica cycle.

Title: FASER: New Eyes for the LHC

Abstract:  Particle colliders have been the workhorse tool of particle physics for over 50 years, and the Large Hadron Collider at CERN has been the focus of attention for decades.  Despite this, in recent years, it has become clear that the physics potential of the LHC is far from being fully explored. In particular, the existing billion dollar detectors are blind to forward collisions, which produce particles along the beamline.  We now know that these collisions are a treasure trove of physics, containing the highest-energy neutrinos ever produced by humans and possible evidence for dark matter, dark sectors, milli-charged particles, and other new particles and forces.  FASER, the Forward Search Experiment, was designed to cover this blind spot. Beginning in 2022, FASER detected the first neutrinos in the history of particle colliders, opening a new window on the high-energy frontier, and started searching for a variety of new particles with world-leading sensitivity.  This talk will describe FASER's recent results, how they complement the traditional LHC program, and the Forward Physics Facility, a proposal to fully realize the potential of forward physics in the coming decade.

Title: Energetic particles, all the way down

Abstract: The aurora is a fascinating display in Earth’s atmosphere that connects to dynamics in the magnetosphere both directly and indirectly. Typically, research is confined to one “end” of the process or the other: the auroral physics in the ionosphere or the particle and wave dynamics in the magnetosphere. In this talk, I will discuss the connection between the two including (1) the generation of energetic precipitation within the ring current and radiation belts, (2) the type of aurora this precipitation produces, and (3) the implications of high-energy precipitation into Earth’s lower atmosphere. By observing and studying the entire chain of events, from magnetospheric driving to the resulting impacts on the atmosphere, we can start to connect seemingly distinct physical processes to each other and gain a better understanding of system-level science. 

Over the last few decades, our knowledge of cosmology and the universe around us has exploded. Through a series of land- and space-based observations, it has become possible to identify a Standard Cosmological Model. However, everything we see today was set up in the very early stages of the evolution of the Universe. 

This lecture will explore key events from those early times, starting with the inflationary universe, which began when the universe was an unimaginably small fraction of a second old. It will also cover ideas about the absence of antimatter, the formation of nuclei, and the eventual formation of galaxies and large-scale structures.

Title: Collision Course: Particle Physics meets Machine Learning

Abstract: Modern machine learning has had an outsized impact on many scientific fields, and particle physics is no exception.  What is special about particle physics, though, is the vast amount of theoretical knowledge that we already have about many problems in the field, as well as the daunting deluge of data coming from flagship experiments like the Large Hadron Collider (LHC).  In this colloquium, I will explain how one can teach a machine to "think like a physicist" by embedding theoretical principles into advanced machine learning architectures.  At the same time, I will advocate that physicists must learn how to "think like a machine" to maximize the physics reach of the LHC.

Title: Quantum System Scaling for Time

Abstract: Laser and quantum sciences have fueled revolutionary developments in atomic, molecular, and fundamental physics. Scaling up quantum systems to ever increasing sizes promises to open new discovery opportunities. Quantum technology has brought many thousands of atoms to coherence times of minutes, it is now also knocking on the door of nuclear physics, heralded by the recent breakthrough of quantum-state-resolved laser spectroscopy of thorium-229 nuclear transition. Using a precision frequency comb in the vacuum-ultraviolet, we coherently excite the thorium nuclear clock transition and connect its frequency directly to today’s most precise atomic clock. This unification of precision metrology and nuclear physics sparks new ideas for testing fundamental physics and promises nuclear-based clock with billions of nuclear absorbers.

Title: The Physics of Superheroes

Abstract: While scientists don’t typically consult comic books when selecting research topics, innovations first introduced in superhero adventures can sometimes find their way off the comic book page and into reality. I’ll describe the real physics that underlies the properties of materials, using examples from Spider-Man, Superman and Gormuu, warrior invader from the planet Kraalo! We’ll describe the physics that gives Spider-Man’s webbing its amazing properties – and subject our analysis to some real-world experimental testing. All this, and the answers to such burning questions as the chemical composition of Captain America’s shield, and who is faster: Superman or the Flash? will be discussed. Superhero comic books often get their science right more often than one
would expect.

Title: Moiré Materials 

Abstract: The advent of two-dimensional materials in recent years has opened a new opportunity to design quantum metamaterials in which many-particle matter waves exhibit strongly-correlated and topologically non-trivial properties that are rare in naturally occurring crystals. For example, two-dimensional van der Waals crystals that are overlaid with a difference in lattice constant or a relative twist form a moiré pattern.  In semiconductors and semimetals, the low-energy electronic properties of these systems are accurately described by Hamiltonians that have the periodicity of the moiré pattern – artificial crystals with lattice constants on the 10 nm scale.  Over the past several years substantial progress has been made in the fabrication of these moiré metamaterials, especially ones based on graphene, hexagonal boron nitride, and transitional metal dichalocogenides (TMDs). Since the miniband widths in both graphene and TMD moiré materials can be made small comparted to interaction energy scales (by mechanisms [1,2] that differ), these materials can be used both for quantum simulation and for quantum design. An important property of moiré materials is that their band filling factors can be tuned over large ranges without introducing chemical dopants, simply by using electrical gates.  

In addition to realizing Mott insulators, density waves, a variety of different types of magnets, and superconductors – states of matter that are familiar from the study of strongly correlated atomic scale crystals – moire materials have emerged as perhaps the best platform uncovered to date for studies of topologically non-trivial matter, especially strongly interacting topologically non-trivial matter. The role of band topology is natural in graphene moires, where it derives from the interesting band topology of graphene monolayers, but has been an unexpected bonus [3] in the case of TMD moires where it derives from twists in the layer degree of freedom. I will discuss the latest developments in this evolving story.
 

Title: Not available at this time.

Abstract: Not available at this time.

Title: Qubits and their surroundings: concepts, challenges, and solutions

Abstract: Quantum computers promise revolutionary advances in computing power, but they are hard to make. One main reason for this difficulty has to do with the environment surrounding the qubits, which can create errors in quantum operations. I will discuss how we think about theenvironment of a qubit, what the environments do, and what can be done about them. As it turns out, efforts to understand and control qubit environments have motivated much of the research in quantum information processing in the past decades, illustrating the great beauty and depth of this topic.