Past Events
| Event | Date | Summary |
| Condensed Matter Seminar: Jie Gao, Missouri University of Science and Technology (University of Missouri – Rolla) | Thu. May 11th, 2017 11:30 am-12:30 pm |
Jie Gao Missouri University of Science and Technology (University of Missouri – Rolla) Tailoring light-matter interaction with metamaterials and metasurfaces Metamaterials and metasurfaces with designed subwavelength nanostructures exhibit intriguing electromagnetic phenomena, such as negative refraction, invisible cloaking, sub-diffraction imaging, near-zero permittivity and hyperbolic dispersion. In this talk, I will present our recent work on tailoring light-matter interaction with metamaterials and metasurfaces, including the realization of enhanced spontaneous emission, ultrasensitive molecule detection, strong plasmon-phonon interaction, optical vortex generation and full-color metasurface hologram. These results present opportunities and challenges in understanding new physics of light-matter interaction in those artificially structured optical materials and realizing many unprecedented applications in nanophotonics. |
| CANCELED: Maosheng Miao, California State University Northridge,Simulate to discover: from new chemistry under high pressure to novel two-dimensional materials | Mon. April 24th, 2017 12:45 am-1:45 am |
CANCELED. Will be rescheduled. Simulate to discover: from new chemistry under high pressure to novel two-dimensional materials
Maosheng Miao Department of Chemistry and Biochemistry California State University Northridge, California 91330, USA
The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry, rooted in the atomic shell structure. Within compounds, Group I elements, for example, invariably assume the +1 oxidation state, and their chemical properties differ completely from those of the p-block elements. |
| David Pace, General Atomics, San Diego, The Fast and the Furious: Energetic Ion Transport in Magnetic Fusion Devices | Wed. April 19th, 2017 12:45 am-1:45 am |
The Fast and the Furious: Energetic Ion Transport in Magnetic Fusion Devices D.C. Pace and the DIII-D National Fusion Facility Team General Atomics, P.O. Box 85608, San Diego, CA 92186-5608, USA David Pace Nuclear fusion has the potential to be an energy source that powers society without generating greenhouse gases or high-level radioactive waste. The tokamak approach to controlled nuclear fusion employs a toroidally-shaped magnetic field configuration to confine plasmas at temperatures beyond 200 million K (20 keV). Future reactors aim to utilize the deuterium-tritium fusion reaction due to its favorable cross-section, |
| Louis F. Piper, Binghamton University, Shining new light on old problems in lithium ion batteries | Mon. April 17th, 2017 12:45 am-1:45 am |
Shining new light on old problems in lithium ion batteries
Louis Piper Binghamton University, State University of New York
Improving the energy storage and release of lithium ion battery is largely limited to the cathode (positive electrode). Commercial high capacity LIBs employ Ni-rich layered oxides (derived from LiCoO2) as cathodes. In these systems, the reversible energy storage capacity is limited to 1 Li+ per transition metal (i.e. Co3+/4+ redox couple). However, only 2/3 of Li+ per redox couple are typically intercalated due to capacity retention issues with fast cycling and high voltages. |
| Nandini Trivedi, The Ohio State University, Novel magnetic phases in spin-orbit coupled oxides | Mon. April 10th, 2017 12:45 pm-1:45 pm |
Novel magnetic phases in spin-orbit coupled oxides Abstract: I will discuss puzzles about magnetism in some of the simplest oxide materials with a single electron in the d-orbital. Starting from a microscopic model of a Mott insulator with both spins and orbitals, I will obtain the effective magnetic Hamiltonian and provide insights into the experimental puzzles. |
| Nate Stern, Northwestern University, Monolayer Semiconductor Opto-Electronics: Controlling Light and Matter in Two-Dimensional Materials | Mon. April 3rd, 2017 12:45 pm-1:45 pm |
Monolayer Semiconductor Opto-Electronics: Controlling Light and Matter in Two-Dimensional Materials Nathaniel Stern Department of Physics and Astronomy, Northwestern University The discovery of monolayer two-dimensional semiconductors of atomic-scale thickness presents a new two-dimensional landscape in which to play with the interaction between light and matter. These nanomaterials at the extreme limit of surface-to-volume ratio exhibit rich optical phenomenology such as layer dependent bandgaps and degenerate, but distinct, valley-polarized excitonic states. The unique features of atomically-thin materials suggest that these layered systems can be exploited to achieve new regimes of light-matter interactions. |
| Paul Kelly, University of Twente, Turning up the heat in first principles Quantum Spin Transport | Wed. March 22nd, 2017 12:45 pm-1:45 pm |
Turning up the heat in first principles Quantum SpinTransport The spin Hall angle (SHA) is a measure of the efficiency with which a transverse spin current is generated from a charge current by the spin-orbit coupling and disorder in the spin Hall effect (SHE). In a study of the SHE for a Pt|Py (Py=Ni80Fe20) bilayer using a first-principles scattering approach, we find a SHA that increases monotonically with temperature and is proportional to the resistivity for bulk Pt. |
| No Seminar, APS March Meeting and Spring Break | Mon. March 13th, 2017 1:00 am-1:00 am |
Continue reading… No Seminar, APS March Meeting and Spring Break |
| Francesca F. Serra, Johns Hopkins University, Control of liquid crystals through topography for optics and assembly | Mon. February 27th, 2017 12:45 pm-1:45 pm |
Control of liquid crystals through topography for optics and assembly |
| Hamza Balci, Kent State University, A Single Molecule Approach to Study Protein, Small Molecule, and G-Quadruplex | Mon. February 20th, 2017 12:45 pm-1:45 pm |
A Single Molecule Approach to Study Protein, Small Molecule, and G-Quadruplex Interactions Hamza Balci Kent State University, Physics Department, Kent, OH
G-quadruplex (GQ) structures are non-canonical nucleic acid secondary structures that form in guanine-rich segments of the genome, most prominently at telomeres. In addition, several hundred thousand potential GQ forming sequences have been identified in human genome, with particularly higher frequency at promoter regions. When GQ structures (GQs) form at telomeres, they cap chromosome ends and are involved in stabilizing these vulnerable regions. Also, GQs have been shown to regulate transcription and translation level gene expression when they form in promoter regions of DNA and 5′-UTR of RNA, |
| Saw-Wai Hla, Ohio University, Operating Individual Quantum Molecular Machines | Mon. February 6th, 2017 12:45 pm-1:45 pm |
Operating Individual Quantum Molecular Machines Saw-Wai Hla Department of Physics & Astronomy, Ohio University, OH 45701, USA and Nanoscience and Technology Division, Argonne National Laboratory, IL 60439, USA. E-mail: hla@ohio.edu , URL: www.phy.ohiou.edu/~hla
A recent emergent research direction is the development of complex molecular machines suitable to operate on solid surfaces. Biological machines have the sizes from tens of nanometers to a few microns –a range where classical machine concepts hold while artificially designed molecular machines can be in the size range of a few nanometers or less, Continue reading… Saw-Wai Hla, Ohio University, Operating Individual Quantum Molecular Machines |
| Mike Boss, NIST, Physics and Impact of Quantitative Magnetic Resonance Imaging | Mon. January 30th, 2017 12:45 pm-1:45 pm |
Physics and Impact of Quantitative Magnetic Resonance Imaging Michael Boss, Applied Physics Division Each year, millions of U.S. patients are scanned using Magnetic Resonance Imaging (MRI), costing billions of dollars. The resultant images are typically qualitative, limiting the ability to compare results across patients, time, and scanners. However, a suite of physical parameters (e.g., relaxation times, diffusion coefficients) are interrogable with magnetic resonance, enabling quantitative imaging biomarkers (QIBs). QIBs can provide threshold values for disease diagnosis, allow meaningful measurement of longitudinal change for evaluating treatment response, Continue reading… Mike Boss, NIST, Physics and Impact of Quantitative Magnetic Resonance Imaging |
| Lucile Savary (MIT) — Michelson Postdoctoral Prize Lecturer | Fri. January 27th, 2017 12:45 pm-1:45 pm |
Quantum Loop States in Spin-Orbital Models on the Honeycomb and Hyperhoneycomb Lattices In the quest for quantum spin liquids, the challenges are many: neither is it clear how to look for nor how to describe them, and definitive experimental examples of quantum spin liquids are still missing. In this talk I will show how to devise a realistic model on the honeycomb lattice whose ground state realizes Haldane chains whose physical supports fluctuate, hence naturally providing the hallmark “fractional excitations” of quantum spin liquids. When taken to the three-dimensional hyperhoneycomb lattice, the ground state becomes a full-fledged symmetry-enriched U(1) quantum spin-orbital liquid, Continue reading… Lucile Savary (MIT) — Michelson Postdoctoral Prize Lecturer |
| Lucile Savary (MIT) — Michelson Postdoctoral Prize Lecturer | Tue. January 24th, 2017 11:00 am-12:00 pm |
Quantum Spin Ice Recent work has highlighted remarkable effects of classical thermal fluctuations in the dipolar spin ice compounds, such as “artificial magnetostatics.” In this talk, I will address the effects of terms which induce quantum dynamics in a range of models close to the classical spin ice point. Specifically, I will focus on Coulombic quantum spin liquid states, in which a highly entangled massive superposition of spin ice states is formed, allowing for dramatic quantum effects: emergent quantum electrodynamics and its associated emergent electric and magnetic monopoles. I will also discuss how random disorder alone may give rise to both a quantum spin liquid and a Griffiths Coulombic liquid–a Bose glass-like phase. Continue reading… Lucile Savary (MIT) — Michelson Postdoctoral Prize Lecturer |
| Michael Snure, AFRL, Two dimensional BN an atomically thin insulator, substrate, and encapsulation layer from growth to application | Mon. January 23rd, 2017 12:45 pm-1:45 pm |
Two dimensional BN an atomically thin insulator, substrate, and encapsulation layer from growth to application Michael Snure Air Force Research Laboratory, Sensors Directorate, Wright Patterson AFB, OH Since free standing graphene was found in 2004, there has been an explosion of research on atomically thin two dimensional (2D) materials based isolated sheets of layered van der Waals solids. The spectacular electrical and thermal transport properties of graphene generated a great deal of hype making it a heavily researched material for ultra-high-speed electronics; however, strong interaction with conventional 3D substrates and the lack of a band gap has proven to degrade properties and limit its usefulness in these devices. |
| Lucile Savary (MIT) — Michelson Postdoctoral Prize Lecturer | Mon. January 23rd, 2017 4:15 pm-5:15 pm |
A New Type of Quantum Criticality in the Pyrochlore Iridates The search for truly quantum phases of matter is one of the center pieces of modern research in condensed matter physics. Quantum spin liquids are exemplars of such phases. They may be considered “quantum disordered” ground states of spin systems, in which zero point fluctuations are so strong that they prevent conventional magnetic long range order. More interestingly, quantum spin liquids are prototypical examples of ground states with massive many-body entanglement, of a degree sufficient to render these states distinct phases of matter. Their highly entangled nature imbues quantum spin liquids with unique physical aspects, Continue reading… Lucile Savary (MIT) — Michelson Postdoctoral Prize Lecturer |