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Dark states in the magnetotransport through triple quantum dots
We consider the transport through a system of three coupled quantum dots in a
perpendicular magnetic field. At zero field, destructive interference can trap
an electron in a dark state -- a coherent superposition of dot states that
completely blocks current flow. The magnetic field can disrupt this
interference giving rise to oscillations in the current and its higher-order
statistics as the field is increased. These oscillations have a period of
either the flux-quantum or half the flux-quantum, depending on the dot
geometry. We give results for the stationary current and for the shotnoise and
skewness at zero and finite frequency.Comment: 7 pages, 7 figure
Atmospheric microwave refractivity and refraction
The atmospheric refractivity can be expressed as a function of temperature, pressure, water vapor content, and operating frequency. Based on twenty-year meteorological data, statistics of the atmospheric refractivity were obtained. These statistics were used to estimate the variation of dispersion, attenuation, and refraction effects on microwave and millimeter wave signals propagating along atmospheric paths. Bending angle, elevation angle error, and range error were also developed for an exponentially tapered, spherical atmosphere
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