Past Events
| Event | Date | Summary |
| (CANCELED) Alexander Govorov, Ohio University, Plasmonic Bio-Assemblies and Metastructures: Chirality, Coherent Transfer of Plasmons and Generation of Hot Electrons | Mon. December 9th, 2019 12:45 pm-1:45 pm |
CANCELED Plasmonic Bio-Assemblies and Metastructures: Chirality, Coherent Transfer of Plasmons and Generation of Hot Electrons Alexander O. Govorov Department of Physics and Astronomy, Ohio University, Athens, USA; govorov@ohio.edu Plasmonic nanostructures and metamaterials are very efficient at absorption and scattering of light. The studies to be presented in this talk concern special designs of hybrid nanostructures with electromagnetic hot spots, where the electromagnetic field becomes strongly enhanced and spatially concentrated. Overall, plasmonic nanostructures with hot spots demonstrate strongly amplified optical and energy-related effects, |
| Luke Bissell, AFRL, Solid State Materials Strategies for Quantum Information | Mon. November 25th, 2019 12:45 pm-1:45 pm |
Solid State Materials Strategies for Quantum Information Luke Bissell, Air Force Research Laboratory In this talk I will first discuss the Air Force Research Laboratory (AFRL) strategy for investment in quantum information research, highlighting activities in the Information (Rome, NY), Space Vehicles and Directed Energy (Albuquerque, NM) and Materials and Manufacturing and Sensors Directorates (Dayton, OH). In the near term, AFRL is pursuing quantum sensing technologies for improved timekeeping and navigation in GPS denied environments. Mid-term investments are focused in architectures for quantum networks, including the entangled photon sources and quantum memories needed to realize them. Continue reading… Luke Bissell, AFRL, Solid State Materials Strategies for Quantum Information |
| Daniel Beller, University of California Merced, Topological defect structure and dynamics in 3D active nematics | Mon. November 11th, 2019 12:45 pm-1:45 pm |
Topological defect structure and dynamics in 3D active nematics Nematic liquid crystals, which are fluids with orientational order, may contain topological defects called disclinations where this order breaks down. While they’re undesirable in LCD screens, disclinations play an essential role in the dynamics of active nematics, non-equilibrium systems with internally driven flows coupled to nematic orientational distortions. Examples include cytoskeletal biofilaments with molecular motors, bacterial colonies, and some eukaryotic cellular tissues. In quasi-2D confinement, disclinations are point-like, and their pair-unbinding and motility drives the chaotic dynamics. In this talk, I will explore how the situation in 3D is even more complex. |
| Mikel Holcomb, West Virginia University, Collaborative efforts in materials physics | Mon. November 4th, 2019 12:45 pm-1:45 pm |
Collaborative efforts in materials physics Due to the collaborative nature of the Holcomb group’s expertise, we explore many significant areas in materials science, including magnetism, magnetoelectricity, topological insulators and other quantum systems. This talk will focus on primarily our beamline efforts, as these often provide the most meaningful results. I will provide a few example cases and discuss our latest discovery of a new form of magnetism. Host: Jesse Berezovsky |
| Alexey Kovalev, University of Nebraska Lincoln, Nonequilibrium spin currents and spin polarization in noncollinear antiferromagnetic insulators | Mon. October 28th, 2019 12:45 pm-1:45 pm |
Nonequilibrium spin currents and spin polarization in noncollinear antiferromagnetic insulators Alexey Kovalev, Department of Physics, University of Nebraska, Lincoln An ability to control spin is important for probing many spin related phenomena in the field of spintronics. Spin-orbit torque is an important example in which spin flows across magnetic interface and helps to control magnetization dynamics. As spin can be carried by electrons, spin-triplet pairs, Bogoliubov quasiparticles, magnons, spin superfluids, spinons, etc., studies of spin currents can have implications across many disciplines. In this talk, I first review the most common ways to generate spin flows and then concentrate on how spin can be controlled via magnons in insulating materials. |
| Mathias Schubert, University of Nebraska-Lincoln, Phonons, free charge carriers, excitons and band-to-band transitions in beta Ga2O3 and related alloys determined by ellipsometry and optical Hall effect | Mon. October 21st, 2019 12:45 pm-1:45 pm |
Phonons, free charge carriers, excitons and band-to-band transitions in beta Ga2O3 and related alloys determined by ellipsometry and optical Hall effect Schubert1,2,3, A. Mock4, S. Knight1, M. Hilfiker1, M. Stokey1, V. Darakchieva2, A. Papamichail2, R. Korlacki1, M.J. Tadjer5, Z. Galazka6, G. Wagner6, N. Blumenschein7, A. Kuramata8, K. Goto8,9, H. Murakami9, Y. Kumagai8, M. Higashiwaki10, A. Mauze11, Y. Zhang11, J. S. Speck11
1Department of Electrical and Computer Engineering, University of Nebraska – Lincoln, Nebraska 68588, USA 2Department of Physics, Chemistry and Biology (IFM), Linkoping University, SE 58183 Linkoping, Sweden 3Leibniz Institute for Polymer Research, |
| No seminar faculty meeting | Mon. October 14th, 2019 12:45 pm-1:45 pm |
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| Guang Bian, University of Missouri, Symmetry-Enforced Dirac Fermions in Nonsymmorphic α-Bismuthene | Mon. September 30th, 2019 12:45 pm-1:45 pm |
Symmetry-Enforced Dirac Fermions in Nonsymmorphic α-Bismuthene |
| Antia Botana, Arizona State University, Mimicking cuprates with low-valence layered nickelates. | Mon. September 23rd, 2019 12:45 pm-1:45 pm |
Mimicking cuprates with low-valence layered nickelates. Antia Botana, Dept. of Physics, Arizona State University, Tempe, AZ The physics behind high-temperature superconducting cuprates remains a defining problem in Condensed Matter Physics. One way of addressing this problem has been to search for alternative transition metal oxides with comparable structures and 3d electron count, proxies for cuprate physics. By means of electronic structure calculations, we propose low-valence layered nickelates as one of the closest analogs to cuprates yet reported. These materials possess a combination of traits that are widely considered as crucial ingredients for high-temperature superconductivity in cuprates: a square-planar nature, |
| Jixin Chen, Ohio University | Mon. September 16th, 2019 12:45 pm-1:45 pm |
Photophysics as a Tool to Measure the Surface-State of Perovskite Nanoparticles Jixin Chen, Department of Physics, Ohio University The photoluminescence (PL) of organolead halide perovskites (OHPs) is sensitive to OHPs’ surface conditions and an effective way to report surface states. OHP is a hot semiconducting material that has a large potential in solar cells and LEDs. Photophysics describes the light-matter interactions in the materials using several phenomena such as absorption, exciton relaxation, emission quantum yield, photoblinking, and photodarkening/photobleaching. In this seminar, Dr. Chen will focus his talk on the photoblinking and photodarkening of perovskite nanoparticles. |
| Joshua Goldberger, The Ohio State University, Axis-dependent conduction polarity in layered materials | Mon. September 9th, 2019 12:45 pm-1:45 pm |
Axis-dependent conduction polarity in layered materials Department of Chemistry and Biochemistry, The Ohio State University, Columbus Layered and two-dimensional materials have emerged as one of the most exciting families of solid-state compounds, due to the plethora of unique physical phenomena found in these materials coupled with advances in the characterization of structure and properties down to the single layer scale. Here, we will describe our efforts in developing new families of these compounds, and our recent discovery of axis-dependent conduction polarity these materials. Electronic materials generally exhibit a single majority carrier type, electrons or holes. |