Title: Enhanced and Extended Strange Metallicity due to Coulomb Repulsion and Disorder

Abstract: I will discuss the problem of strange metals, where the traditional notion of Fermi liquid quasiparticles ceases to apply. I will view the problem through the lens of a model of electrons with Hubbard-U Coulomb repulsion and a disordered Yukawa coupling to a two-dimensional bosonic bath, which can be solved in an extended dynamical mean field theory scheme. The model exhibits a quantum critical point, at which the repulsive component of the electron interactions strongly enhances the effects of the quantum critical bosonic fluctuations on the electrons, leading to a breakdown of Fermi liquid physics and the formation of a strange metal with `Planckian' quasiparticle decay rates at low temperatures, although with no holographic dual. Furthermore, the eventual Mott transition that occurs as the repulsion is increased seemingly bounds the maximum decay rate in the strange metal. I will also discuss some applications and collaborations based on this work to the iron-based superconductors and moire materials. Time permitting, I will conclude with future directions to include nonlocal effects.  

Title: Strongly correlated topological phenomena in graphene multilayers

Abstract: Multilayer rhombohedral graphene has recently been experimentally demonstrated to host a panoply of strongly correlated and topological phenomena. In the presence of alignment to hBN, this platform exhibits Chern insulators and the fractional quantum anomalous Hall effect. On the other hand, signatures of unconventional (chiral) superconductivity arise in pristine multilayers. From a theoretical standpoint, several key issues are under active debate. In particular, what is the nature of the moire effect in this setting? How can we understand the emergence of these exotic topological states? I will discuss our progress towards resolving these questions, and highlight broader implications for other material platforms.

The K-Week College Meeting is where it all begins. Meet your Arts and Sciences family, grab free swag and snacks, and get ready for an unforgettable start.

Thursday, August 21, 2025

1 PM @ Gatton Student Center, Barker Plaza

Attendance will be taken

Tailgate with Arts and Sciences alumni and friends before the Cats take on the Texas Longhorns!

Join Dean Ana Franco-Watkins for tailgate food and drinks, games and A&S giveaways! All College of Arts and Sciences alumni are welcome to attend.

Saturday, October 18, 2025

Tailgate and kickoff times TBD

• 4:00 p.m. – Tent opens; drinks served.
• 5:00 p.m. – Dinner served.

Gluck Equine Research Center Lawn | Corner of Nicholasville Road and Farm Road

A&S Alumni Tailgate is for alumni and friends of the College of Arts and Sciences and their guests.

RSVP

Dr. Stephen Taylor, Vanderbilt University

Title: Charting the Gravitational-wave Universe At Light-year Wavelengths

Abstract: The Universe is thrumming with gravitational waves. June 2023 brought the first evidence for an all-sky background of nanohertz-frequency gravitational waves, discovered by collaborations including the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) and groups in Europe, Australia, India, and China. This was an endeavor decades in the making, requiring painstakingly precise timing observations of scores of millisecond pulsars across the Milky Way using flagship radio telescopes. While the results from separate groups are consistent with one another—and the leading interpretation of a population of supermassive black-hole binaries as the source—the observations provoke many new questions. Do the results imply a population of binaries more massive than expected? What are the observational milestones as the first individually resolvable binary signals come into focus? Can we link these signals to their host galaxies or electromagnetic counterparts? In this talk, I will chart the path to discovery, reflect on what we have learned since our announcement, and explore the exciting opportunities and synergies ahead—including the role of next-generation radio instruments and space-borne gravitational-wave missions.

Dr. Zhoudunming (Kong) Tu, Brookhaven National Laboratory

Title: Exciting the Entangled Vacuum - A New Era in Understanding Visible Matter

Abstract: Not until quite recently was the vacuum recognized as anything more than empty space. Today, we understand it as a dynamic medium, filled with fluctuating fields and virtual particle pairs that shape the very structure of our universe. These invisible pairs break a fundamental symmetry of nature—chiral symmetry—and are thought to generate more than 99% of the mass of the visible universe. Yet, how this hidden mechanism connects to the confinement of quarks inside protons, neutrons, and other particles remains one of the deepest unsolved problems in physics.

In this talk, I will present new insights into this question using high-energy particle collisions at the Relativistic Heavy Ion Collider (RHIC). Such collisions can briefly liberate the virtual quark–antiquark pairs of the vacuum, which then bind together into hadrons such as Λ hyperons. Recent results from these studies open an experimental window into the quantum structure of the vacuum, with far-reaching implications for our understanding of mass, matter, and the strong force described by Quantum Chromodynamics.