Nuclear physics of stellar explosions
Wednesday, April 25, 2018
118 Nieuwland Science Hall
Dr. Artemis Spyrou, Associate Professor and Associate Director for Education, Department of Physics, Michigan State University, will answer questions that are driving the field of nuclear astrophysics. The talk will focus on the nuclear physics aspects of heavy element nucleosynthesis in different explosive environments. Dr. Spyrou will present experiments performed at the National Superconducting Cyclotron Laboratory (NSCL), at Michigan State University. The NSCL is a rare isotope beam facility that can give unique access to nuclei involved in astrophysical processes. She will discuss recent experiments, new initiatives, and where we expect to go in the future, with a particular focus on the recent discover of the merging of two neutron stars.
Control and local measurements of the spin chemical potential in a magnetic insulator
Thursday, Jan. 25, 2018
123 Nieuwland Science Hall
Chunhui Du, Postoctoral fellow, Department of Physics, Harvard University, will discuss single-spin magnetrometry based on nitrogen-vacancy centers in diamond as a new and generic platform to locally spin chemical potentials. This essentially determines the flow of spin currents. Du will describe he her lab uses the platform to investigate magnons in a magnetic insulator YIG on a 100-nanometer length scale.
Optoelectronics of Hybrid Metal Halide Pervskites for Photovoltaics
Monday, Jan. 15, 2018
118 Nieuwland Science Hall
Hybrid metal halide perovskites have shown extraordinary success as active layers in solar cells, with power conversion efficiencies rivalling existing silicon technologies. A benefit of perovskites is that they are comprised of low-cost, earth abundant materials, and perovskite thin films are easily synthesized with simple starting materials. Additionally, they exhibit exceptional optoelectronic properties, which include strong absorption across the entire visible spectrum, long charge carrier lifetimes, and high charge-carrier mobilities. Optical-pump/THz-probe (OPTP) spectroscopy has proven to be an essential technique for studying the charge-carrier dynamics and charge-carrier mobility in many of these materials including lead-based, tin-based, two-dimensional, and mixed-halide/mixed-cation perovskites. These studies have determined that the charge-carrier mobility and charge-carrier recombination dynamics are strongly dependent on chemical composition, defect density band structure, and crystallinity.
January 25 - Chunhui Du, Harvard University (More information to come)
Stability in the Homology of Configuration Spaces
Wednesday, Nov. 15, 2017
127 Hayes-Healy Hall
4 p.m., following the departmental tea at 3:30 p.m. in Hurley Hall lounge, room 257
Jennifer Wilson, of Stanford University, will illustrate some patterns in the homology of the space F_k(M) of ordered k-tuples of distinct points in a manifold M. For a fixed manifold M, as k increases, we might expect the topology of the configuration spaces F_k(M) to become increasingly complicated. Church and others showed, however, that when M is connected and open, there is a representation-theoretic sense in which the homology groups of these configuration spaces stabilize. In this talk I will explain these stability patterns, and describe higher-order stability phenomena -- relationships between unstable homology classes in different degrees -- established in recent work joint with Jeremy Miller. This project was inspired by work-in-progress of Galatius-Kupers-Randal-Williams.
A Conversation with Lisa Randall
Monday, Sept. 25, 2017
A renowned scientist and author, Professor Lisa Randall studies theoretical particle physics and cosmology at Harvard University. Her research connects theoretical insights to puzzles in our current understanding of the properties and interactions of matter, as well as explores ways to experimentally test these ideas at the Large Hadron Collider and elswhere.
She will be joined on stage by Notre Dame physicist Ani Aprahamian. A book signing will follow.