Novel Radiation-induced Magnetoresistance Oscillations in a Nondegenerate 2DES on Liquid Helium

We report the observation of novel magnetoresistance oscillations induced by the resonant inter-subband absorption in nondegenerate 2D electrons bound to the surface of liquid helium. The oscillations are periodic in 1/B and originate from the scattering-mediated transitions of the excited electrons into the Landau states of the first subband. The structure of the oscillations is affected by the collision broadening of the Landau levels and by many-electron effects.Comment: 4 figure

Justification optimal operating parameters of the conveyor, which is the mechanism of the header for two-phase harvesting by batch method, taking into account the minimization of losses of grain

The object of research is the conveyor, which is the mechanism of the header for two-phase harvesting by batch method. The aim of the research is to develop the design and technological process of the roll portion header, the most suitable for the conditions of arid climate with the justification of its main operating parameters. In the conditions of the steppe zone of the southern Urals, a separate method of harvesting grain crops is more preferable. The analysis of the structures windrowers allowed to develop a portion of the header. The technological process as a portion of the header includes two phases - mowing and subsequent accumulation of the grain mass on the conveyor, and then upload. The unloaded portions are joined with the stacked in the previous passage - this is how the roll strip is formed. This option of laying the roll can reduce the number of passes in the selection of about 4-5 times in comparison with the basic technology. This allows you to reduce the cost of selection and reduce the impact of heavy machinery on the soil. A special role in the work of the header plays a conveyor. It is established that the thickness of the layer of stems on the Reaper conveyor depends on the working length of the conveyor and the speed of movement of the unit on the field, the density and diameter of the stalk, the density of laying on the conveyor. © The Authors, published by EDP Sciences

Photon-induced vanishing of magnetoconductance in 2D electrons on liquid He

We report on a novel transport phenomenon realized by optical pumping in surface state electrons on helium subjected to perpendicular magnetic fields. The electron dynamics is governed by the photon-induced excitation and scattering-mediated transitions between electric subbands. In a range of magnetic fields, we observe vanishing longitudinal conductivity sigma_xx. Our result suggests the existence of radiation-induced zero-resistance states in the nondegenerate 2D electron system.Comment: 4 pages, 5 figure

On the electric charge of quantized vortices and the dipole moment of vortex pairs and rings in a magnetic field

It is shown that, in the presence of a magnetic field, a quantized vortex line in a superfluid liquid acquires a linear polarization charge, which is localized near the vortex axis over a length on the order of the coherence length. It is found that the total charge of a rectilinear vortex is nonzero, while the vortex pair and vortex ring have a nonzero dipole moment. The electric fields of rectilinear vortices near the end surface of a cylindrical vessel filled with a superfluid liquid are calculated. The electric polarization of superfluid systems in the presence of thermally activated vortex pairs and vortex rings has been studied. It is shown that such a polarization arises in the presence of relative motion of the normal and superfluid components.Comment: 16 pages, 3 figure