Bulletin of the American Physical Society
14th Annual Meeting of the Northwest Section of the APS
Volume 57, Number 7
Thursday–Saturday, October 18–20, 2012; Vancouver, British Columbia, Canada
Session B1: Welcome and Plenary Session I |
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Chair: Oscar Vilches, University of Washington Room: SFU Harbour Centre 1900 Fletcher Challenge Theatre |
Friday, October 19, 2012 8:25AM - 8:30AM |
B1.00001: Welcome |
Friday, October 19, 2012 8:30AM - 9:06AM |
B1.00002: Using the Aurora to Remote Sense Near-Earth Space Invited Speaker: Eric Donovan The Earth's magnetosphere is formed by the interaction of the solar wind and Earth's magnetic field. Sitting like a giant wind sock in the solar wind, the magnetosphere is an enormous and dynamic region. The processes at work within the magnetosphere serve as exemplars of phenomena that happen throughout the cosmos, and have consequences in the upper atmosphere. One of those is the aurora, a truly global and multi-scale phenomenon that we are only beginning to understand. Of all the countries on Earth, Canada has the largest region of land under the auroral zone, something Canadian scientists have capitalized on for more than fifty years. In this talk, I will outline how we use observations of the aurora to remote sense the magnetosphere, focusing on Canadian ground-based and space-based programs that provide remarkable images of this beautiful natural phenomenon. [Preview Abstract] |
Friday, October 19, 2012 9:06AM - 9:42AM |
B1.00003: Quantum hydrodynamics in dilute-gas Bose-Einstein condensates Invited Speaker: Peter Engels The peculiar dynamics of superfluids are a fascinating research topic. Since the first generation of a dilute gas Bose-Einstein condensate (BEC) in 1995, quantum degenerate atomic gases have taken the investigation of quantum hydrodynamics to a new level. The atomic physics toolbox has grown tremendously and now provides unique and powerful ways to explore nonlinear quantum systems. As an example, pioneering results have recently revealed that the counterflow between two superfluids can be used as a well controlled tool to access the rich dynamics of vector systems. New structures, such as beating dark-dark solitons which only exist in multicomponent systems and have never been observed before, can now be realized in the lab for the first time. Furthermore, the field of nonlinear quantum hydrodynamics is entering new regimes by exploiting Raman dressing as a tool to directly modify the dispersion relation. This leads to the generation of spin-orbit coupled BECs, artificial gauge fields, etc. that are currently receiving tremendous interest due to their parallels to complex condensed-matter systems. Studies of quantum hydrodynamics help to develop a profound understanding of nonlinear quantum dynamics, which is not only of fundamental interest but also of eminent importance for future technological applications, e.g. in telecommunication applications using optical solitons in fibers. This talk will showcase some ``classic'' hallmark results and highlight recent advances from the forefront of the field. [Preview Abstract] |
Friday, October 19, 2012 9:42AM - 10:18AM |
B1.00004: Material and Optical Properties of ZnO-Based Alloys Invited Speaker: Leah Bergman ZnO is emerging as one of the materials of choice for UV applications. It has a relatively benign chemical nature, a deep excitonic energy level, and a direct bandgap of $\sim$ $3.4$ eV. The latter two properties make ZnO a highly efficient light-emitter at room and above room temperatures. Alloying ZnO with certain atomic constituents has the potential to add new optical and electronic functionalities to ZnO. This work will focus on two alloy systems of ZnO: one is Mg(x)Zn(1-x)O, and the other is ZnS(1-x)O(x). The x in the formula is the percent composition of the alloy constituents; upon changing the composition, the bandgap and the optical properties can be tailored from those of one end member to the other. At the low Mg composition range, the Mg(x)Zn(1-x)O alloy has the hexagonal wurtzite structure and a bandgap that is tunable in the range of $\sim$ $3.4$ (that of ZnO) up to approximately $4$ eV. At the high composition range the alloy forms with the cubic NaCl structure, and importantly its bandgap shifts into the deep UV range up to $7.4$ eV (that of MgO). Thus, Mg(x)Zn(1-x)O can provide an alloy system with bandgaps and bandedge photoluminescence spanning the range of $3.4$ eV to $7.4$ eV that are achieved via the choice of the composition x. However, due to the two different crystal structures of the end members, ZnO with the wurtzite and MgO with the cubic structure, at intermediate composition range the alloy is phase segregated. The other alloy system to be discussed is the ZnS(1-x)O(x). The bandgap of ZnO is $3.4$ eV and that of ZnS is $3.8$ eV; upon alloying ZnO with sulfur, the bandgap behavior exhibits a strong deviation from linearity due to the large difference in atomic size and chemical characteristics of the alloy constituents. Unlike Mg(x)Zn(1-x)O, the ZnS(1-x)O(x) is a highly lattice mismatched system that results in a strong bowing of its bandgap toward the visible range at the green-blue part of the spectrum. In this research, we present studies of the material and optical properties of both alloys. The issue of solubility and phase segregation studied via X-ray diffraction, photoluminescence, and atomic imaging, is addressed. The optical properties that were studied via absorption and photoluminescence are discussed. The optical properties studied include bandgap tailoring, the nature of the optical emission specifically exciton and defect photoluminescence, and the phonon dynamics of the alloys. [Preview Abstract] |
Friday, October 19, 2012 10:18AM - 10:48AM |
B1.00005: BREAK |
Friday, October 19, 2012 10:48AM - 11:24AM |
B1.00006: Recent LHC results Invited Speaker: Anadi Canepa What is the Universe made of? What is the nature of matter? How can we explain the matter vs antimatter asymmetry? Are there extra dimensions of space-time? The Large Hadron Collider (LHC) by recreating the same conditions as those soon after the Big Bang has the potential to answer these questions. The LHC is the highest energy proton-proton collider in the World. Collisions are recorded by the ATLAS and CMS detectors, which are both unprecedented in scale and complexity. The data recorded in 2011 and 2012 lead to the discovery of a Higgs-boson like resonance assumed to be the key ingredient for the generation of mass. Thanks to the excellent performance of the accelerator and of the detectors, future searches have the potential to discover new phenomena, such as Supersymmetry or extra dimensions. We live in a time when the exploration of fundamental particles and their interactions can lead toward a revolutionary new understanding of the universe. [Preview Abstract] |
Friday, October 19, 2012 11:24AM - 12:00PM |
B1.00007: The Experiences of an Entrepreneurial Physicist Invited Speaker: Moe Kermani The majority of pre- and post-graduate training in physics is focused on the acquisition of hard skills necessary to pursue academic research within a specific discipline of the broader field. Often many physics graduates view a career transition from academia to the private sector with much consternation. In this presentation, Moe Kermani will share his experience in making the transition and discuss how elements of post graduate training in physics provide a good foundation for success as an entrepreneur. This presentation is primarily aimed at young physicists and graduate students that are considering a transition from the academic sector to the world of technology startups. [Preview Abstract] |
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