552 research outputs found
On stability of the neutron rich Oxygen isotopes
Stability with respect to neutron emission is studied for highly
neutron-excessive Oxygen isotopes in the framework of Hartree-Fock-Bogoliubov
approach with Skyrme forces Sly4 and Ska. Our calculations show increase of
stability around 40O.Comment: 5 pages, 3 figure
Universal Angular Probability Distribution of Three Particles near Zero Energy Threshold
We study bound states of a 3--particle system in described by
the Hamiltonian ,
where the particle pair has a zero energy resonance and no bound
states, while other particle pairs have neither bound states nor zero energy
resonances. It is assumed that for a converging sequence of coupling constants
the Hamiltonian has a sequence of
levels with negative energies and wave functions , where the
sequence totally spreads in the sense that for all . We
prove that for large the angular probability distribution of three
particles determined by approaches the universal analytical
expression, which does not depend on pair--interactions. The result has
applications in Efimov physics and in the physics of halo nuclei
Using satellite radiometric and ground based lidar measurements for detection of cirrus clouds, containing ensembles of preferred oriented ice particles
In this paper present an example of joint analysis of the data of high-level cloud sensing with a ground based polarization lidar of Tomsk State University and satellite radiometer MODIS
Spin-orbit Hanle effect in high-mobility quantum wells
We study the depolarization of optically oriented electrons in quantum wells
subjected to an in-plane magnetic field and show that the Hanle curve
drastically depends on the carrier mobility. In low-mobility structures, the
Hanle curve is described by a Lorentzian with the width determined by the
effective g-factor and the spin lifetime. In contrast, the magnetic field
dependence of spin polarization in high-mobility quantum wells is nonmonotonic:
The spin polarization rises with the magnetic field induction at small fields,
reaches maximum and then decreases. We show that the position of the Hanle
curve maximum can be used to directly measure the spin-orbit Rashba/Dresselhaus
magnetic field.Comment: 4 pages, 3 figure
Non-exponential spin relaxation in magnetic field in quantum wells with random spin-orbit coupling
We investigate the spin dynamics of electrons in quantum wells where the
Rashba type of spin-orbit coupling is present in the form of random nanosize
domains. We study the effect of magnetic field on the spin relaxation in these
systems and show that the spatial randomness of spin-orbit coupling limits the
minimum relaxation rate and leads to a Gaussian time-decay of spin polarization
due to memory effects. In this case the relaxation becomes faster with increase
of the magnetic field in contrast to the well known magnetic field suppression
of spin relaxation.Comment: published version, minor change
Measurement of ozone concentration in the lower stratosphere - upper troposphere
We describe an ozone lidar and consider an algorithm for retrieving the ozone concentration, taking into consideration the aerosol correction. Results of lidar measurements at wavelengths 299 and 341 nm well agree with model estimates, indicating that ozone is sensed with acceptable accuracies in the altitude range of about 6-18 km. It should be noted that the retrieved profiles of altitude distribution of ozone concentration more closely resemble those from satellite data than according to Krueger model. A lidar is developed and put into operation at Siberian Lidar Station (SLS) to measure the vertical ozone distribution (VOD) in the upper troposphere-lower stratosphere. Sensing is performed according to the method of differential absorption and scattering at wavelength pair 299/341 nm, which are respectively the first and second Stokes components of stimulated Raman scattering (SRS) conversion of the fourth harmonic of Nd:YAG laser (266 nm) in hydrogen
Dynamic ferromagnetic proximity effect in photoexcited semiconductors
The spin dynamics of photoexcited carriers in semiconductors in contact with
a ferromagnet is treated theoretically and compared with time-dependent Faraday
rotation experiments. The long time response of the system is found to be
governed by the first tens of picoseconds in which the excited plasma interacts
strongly with the intrinsic interface between semiconductor and ferromagnet in
spite of the existence of a Schottky barrier in equilibrium
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