1,075 research outputs found
Gate tunability of stray-field-induced electron spin precession in a GaAs/InGaAs quantum well below an interdigitated magnetized Fe grating
Time-resolved Faraday rotation is used to measure the coherent electron spin
precession in a GaAs/InGaAs quantum well below an interdigitated magnetized Fe
grating. We show that the electron spin precession frequency can be modified by
applying a gate voltage of opposite polarity to neighboring bars. A tunability
of the precession frequency of 0.5 GHz/V has been observed. Modulating the gate
potential with a gigahertz frequency allows the electron spin precession to be
controlled on a nanosecond timescale
Mode Spectroscopy and Level Coupling in Ballistic Electron Waveguides
A tunable quantum point contact with modes occupied in both transverse
directions is studied by magnetotransport experiments. We use conductance
quantization of the one-dimensional subbands as a tool to determine the mode
spectrum. A magnetic field applied along the direction of the current flow
couples the modes. This can be described by an extension of the Darwin-Fock
model. Anticrossings are observed as a function of the magnetic field, but not
for zero field or perpendicular field directions, indicating coupling of the
subbands due to nonparabolicity in the electrical confinement.Comment: 4 pages, 3 figure
Orbital assembly and maintenance study
The requirements, conceptual design, tradeoffs, procedures, and techniques for orbital assembly of the support structure of the microwave power transmission system and the radio astronomy telescope are described. Thermal and stress analyses, packaging, alignment, and subsystems requirements are included along with manned vs. automated and transportation tradeoffs. Technical and operational concepts for the manned and automated maintenance of satellites were investigated and further developed results are presented
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