September 19
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Jean Heremans, Department of Physics, Ohio University, Athens,
Ohio
Hydrodynamic pumping of a quantum Fermi liquid in a semiconductor heterostructure
Abstract: We present experimental results for a novel pumping mechanism in two-dimensional Fermi liquids, phenomenologically reminiscent of the Bernoulli pumping effect in classical fluids. The experiments are performed at low temperatures, on mesoscopic geometries defined on high mobility two-dimensional electron systems in GaAs/AlGaAs heterostructures. The pumping force in the Fermi liquid, measured as a voltage signal, is a linear function of the applied current. This is fundamentally different from the Bernoulli effect in classical liquids, where the response is nonlinear and quadratic in terms of the velocity. To theoretically describe the observed phenomenon, we treat a Fermi liquid in the framework of the Boltzmann equation in the relaxation time approximation. |
October 3
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John Scofield, Department of Physics, Oberlin College,
Oberlin, Ohio
Energy performance for Oberlin's Lewis Center
Abstract:
In January 2000 Oberlin College completed construction on the Adam Joseph Lewis Center for Environmental Studies. The building, which contains a dreamlist of energy-efficient technologies, has been put forward as model of sustainable architecture. The designers of the building intend that its rooftop photovoltaic array will one day generate more energy than it consumes.
In this talk I will present performance data on the building energy systems, both energy generation and consumption. In addition I will discuss various design aspects of the building, highlighting strengths and weaknesses. I will conclude by sharing some general lessons that came out of this design process.
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October 31
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Liming Dai, Department of Polymer Engineering, University of Akron
Optoelectronic polymers and aligned carbon nanotubes
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Rescheduled:November 21
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Stuart Tessmer, Department of Physics, Michigan State University,
Lansing, Michigan
Charge Imaging of a 2D Electron System
Abstract:
Two-dimensional electron systems (2DES) formed in GaAs heterostructures
are an ideal laboratory to study many-particle physics in lower
dimensions. The vast majority of experimental work has focussed on
transport properties - of which the integer and fractional quantum
Hall effects represent spectacular examples. In contrast, scanning probe
methods can map out pictures of the electronic properties in real space.
This talk focuses on advancements we have made using Charge
Accumulation Imaging, a capacitance-based probe that is sensitive to the
local density of states and compressibility of the charge carriers
within the 2DES.
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December 5 (3:30 p.m., Ayer 112)
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Jianping Zhu, Department of Theoretical and Applied Mathematics,
University of Akron.
Parallel computing and its application to
numerical solution of hydrodynamics formulation
of the time-dependent Schroedinger equation
Abstract:
Parallel computing has become an indispensable tool for large-scale
modeling and computational simulations of various applications in science
and engineering. In this talk, the speaker will give a brief review of the
history and the latest development in parallel and distributed computing, and then
discuss its application to the solution of the hydrodynamics formulation
of time-dependent Schrödinger equation.
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