3,266 research outputs found
High-frequency oscillations in low-dimensional conductors and semiconductor superlattices induced by current in stack direction
A narrow energy band of the electronic spectrum in some direction in
low-dimensional crystals may lead to a negative differential conductance and
N-shaped I-V curve that results in an instability of the uniform stationary
state. A well-known stable solution for such a system is a state with electric
field domain. We have found a uniform stable solution in the region of negative
differential conductance. This solution describes uniform high-frequency
voltage oscillations. Frequency of the oscillation is determined by antenna
properties of the system. The results are applicable also to semiconductor
superlattices.Comment: 8 pages, 3 figure
On the nature of the solar-wind-Mars interaction
Plasma measurements near Mars on the U.S.S.R. Mars-2, -3, and -5 spacecraft are considered. The data are compared with simultaneous magnetic measurements. Strong evidence is obtained in favor of a direct interaction and mass exchange between the solar wind plasma and the gaseous envelope of Mars
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