Dr. Adam Smercina, Space Telescope Science Institute

Title: A New Era of Galaxy Evolution using Resolved Stars

Abstract: The varied and dynamic evolutionary histories of galaxies give rise to their stunning diversity in the present-day universe. Inferring these histories requires accessing the information encoded in their longest-lived visible components: stars. We are in an exciting new frontier, with a fleet of current and upcoming observatories capable of accessing the resolved stellar populations within and around external galaxies. In this talk, I will first summarize my efforts to chart the merger histories of nearby galaxies by surveying the stars in their accreted halos, including the exciting potential of the upcoming Roman Space Telescope. I will then discuss my efforts to trace the evolution of these galaxies star formation and structure, particularly as a consequence of their merger histories, through high-resolution surveys of their main bodies. In particular, I will highlight several large programs with JWST, which has opened up an exciting new frontier for this science. Over the next decade, these efforts with JWST and Roman have the potential to transform our view of galaxy evolution. To close, I will discuss how this current pioneering work with JWST will pave way for the next paradigm shift in resolved star science: the Habitable Worlds Observatory.

Dr. Erik Henriksen, Washington University

Title: Thermal transport in atomically thin materials

Abstract: Inspired by the potential to study quantum spin liquid-related phenomena in unusual magnetic materials, we are developing methods to measure thermal properties of single- and few-layer atomically thin materials as well as thicker flakes. We will briefly introduce the Kitaev-type quantum spin liquid and the most promising material candidate at the moment, a-RuCl3, and then review some recent experimental progress including a surprisingly large and useful charge transfer when a-RuCl3 is placed in proximity to other materials. The remainder of the talk will cover our latest work on a technique to simultaneously measure the thermal conductivity and specific heat in suspended quasi-2D systems starting with SiN membranes and moving on to flakes of a-RuCl3, hexagonal boron nitride and also the antiferromagnet FePS3.

Abstract: Synthetic DNA nanotechnology facilitates the design and fabrication of nanoscale particles and devices with diverse applications. Leveraging a growing toolkit of DNA self-assembly methods, it is possible to construct both two- and three-dimensional structures ranging from nanometer to micron scales. The biophysical and biochemical properties of DNA — combined with its compatibility with various organic and inorganic nanoparticles and its predictable base-pairing rules — have made it an ideal material for single-molecule studies, photonics, plasmonics, synthetic biology and healthcare applications. In this work, we present our efforts in developing DNA-based platforms to organize inorganic and organic nanoparticles and biosensors precisely. We investigate how these DNA scaffolds can control the positioning and orientation of nanoparticles to enhance their photophysical properties. Additionally, we explore the behavior of DNA nanostructures when introduced into mammalian cell cytosol, a critical step toward creating biocompatible delivery systems for therapeutic and diagnostic purposes. Finally, we will discuss our recent efforts in building gene-encoded DNA nanoparticles, a promising advancement in the development of targeted delivery systems.

Website: https://www.mathurnanolab.com/

Dr. Roger Pynn, Indiana University Bloomington

Title: What are Entangled Neutrons, Anyway?

Abstract: For more than 75 years, neutron scattering has been a powerful tool for probing the positions 
and dynamics of atoms, as well as the magnetic fields that shape material properties. In 
parallel, advances in light optics have increasingly harnessed the quantized nature of photons 
to achieve higher precision and uncover new phenomena. Can similar quantum ideas be 
applied to neutrons? Remarkably, the spin, momentum, and energy of individual neutrons can 
indeed be placed into entangled, Bell-like states. In this talk, I will describe how such 
entanglement has been realized experimentally, and how we validated its existence.
The challenge now is to exploit these mode-entangled neutrons to access new forms of 
information. Recent theoretical work suggests that entangled neutrons could uniquely probe 
electron spin entanglement in specific systems—though experimental confirmation remains to 
be achieved. Still, entanglement has already enabled measurements that would have been 
impossible otherwise. As one example, I will present the first observation of a giant Goos–
Hänchen effect for matter waves and indicate prospects for applying similar techniques to 
materials of scientific and technological relevance. Looking forward, these methods will be 
especially valuable at the next-generation neutron source now being planned at Oak Ridge 
National Laboratory.

Speaker: Dr. Xiaomeng Liu (Cornell)

Title: Superconductivity and Ferroelectric Orbital Magnetism in Semimetallic Rhombohedral Hexalayer Graphene

Abstract: Rhombohedral multilayer graphene has emerged as a promising platform for exploring correlated and topological quantum phases, enabled by its Berry-curvature-bearing flat bands. While prior work has focused on separated conduction and valence bands, we probe the semimetallic regime of rhombohedral hexalayer graphene. We uncovered a rich phase diagram dominated by flavor-symmetry breaking and an electric-field-driven band inversion. Near this inversion, we find a superconducting-like state confined to a region with emergent electron and hole Fermi surfaces. In addition, two multiferroic orbital-magnetic phases are observed: a ferrovalley state near zero field and a ferroelectric state at large fields around charge neutrality. The latter shows electric-field-reversible magnetic hysteresis, consistent with a multiferroic order parameter.

Dr. Shahnawaz Rather, The University of Kentucky

Title: From Coherence to Correlation: Electron-Nuclear Dynamics in Photoinduced Processes

Abstract: Researchers have long pondered whether quantum mechanics might be relevant to the functioning of chemical and biological systems. This idea has fascinated scientists and the public alike, yet it has proven difficult to move beyond speculation and address the central question of functionally relevant quantum effects unequivocally. The challenge has been that realistic chemical or biological systems exhibit enormous energetic disorder, preventing quantum coherence effects from surviving over functionally relevant timescales. However, recent work has indicated that coherence phenomena can appear differently from what researchers initially expected. Rather than manifesting or functioning as quantum bits, coherence effects in molecular systems appear to involve electron-nuclear correlations that can be robust and functionally relevant.

I will present the state of recent discoveries that extend beyond the extensively studied photosynthetic systems. I argue that electron transfer reactions occurring on ultrafast timescales provide a profound basis for understanding electron–nuclear correlations and demonstrate how vibrations can dictate reaction outcomes. I will discuss electron-nuclear correlations through the spin-vibronic effect and how it regulates singlet–triplet conversion in binuclear transition-metal complexes. I will also describe how electron-nuclear interactions can drive energy flow in photocatalysts from a light-harvesting site to a reaction site by bridging the two entities via vibronic delocalization. Toward the end, I will share some of our recent results on shifting vibronic resonances in singlet fission. I will conclude with a forecast that order on the quantum-mechanical scale, even in energetically disordered systems, can emerge from robust electron-nuclear correlations. This understanding could ultimately enable the design of structural control elements for enhanced functioning of energy-conversion systems.