773 research outputs found
Multiqubit Spin
It is proposed that the state space of a quantum object with a complicated
discrete spectrum can be used as a basis for multiqubit recording and
processing of information in a quantum computer. As an example, nuclear spin
3/2 is considered. The possibilities of writing and reading two quantum bits of
information, preparation of the initial state, implementation of the "rotation"
and "controlled negation" operations, which are sufficient for constructing any
algorithms, are demonstrated.Comment: 7 pages, PostScript, no figures; translation of Pis'ma Zh. Eksp.
Teor. Fiz. 70, No. 1, pp. 59-63, 10 July 1999; (Submitted 29 April 1999;
resubmitted 2 June 1999
On the electronic properties of GaSb irradiated with reactor neutrons and its charge neutrality level
The electronic properties and the limiting position of the Fermi level in p-GaSb crystals irradiated with full-spectrum reactor neutrons at up to a fluence of 8.6 × 1018 cm−2 are studied. It is shown that the irradiation of GaSb with reactor neutrons results in an increase in the concentration of free holes to p lim = (5−6) × 1018 cm−3 and in pinning of the Fermi level at the limiting position F lim close to E V + 0.02 eV at 300 K. The effect of the annealing of radiation defects in the temperature range 100–550°C is explored
Lateral distribution of high energy muons in EAS of sizes Ne approximately equals 10(5) and Ne approximately equals 10(6)
Muon energy spectra and muon lateral distribution in EAS were investigated with the underground magnetic spectrometer working as a part of the extensive air showers (EAS) array. For every registered muon the data on EAS are analyzed and the following EAS parameters are obtained, size N sub e, distance r from the shower axis to muon, age parameter s. The number of muons with energy over some threshold E associated to EAS of fixed parameters are measured, I sub reg. To obtain traditional characteristics, muon flux densities as a function of the distance r and muon energy E, muon lateral distribution and energy spectra are discussed for hadron-nucleus interaction model and composition of primary cosmic rays
Vacuum energy and spectral function sum rules
We reformulate the problem of the cancellation of the ultraviolet
divergencies of the vacuum energy, particularly important at the cosmological
level, in terms of a saturation of spectral function sum rules which leads to a
set of conditions on the spectrum of the fundamental theory. We specialize the
approach to both Minkowski and de Sitter space-times and investigate some
examples.Comment: 11 pages, revtex4, no figures, version to be published on PR
The oxygen isotope effect on critical temperature in superconducting copper oxides
The isotope effect provided a crucial key to the development of the BCS
(Bardeen-Cooper-Schrieffer) microscopic theory of superconductivity for
conventional superconductors. In superconducting cooper oxides (cuprates)
showing an unconventional type of superconductivity, the oxygen isotope effect
is very peculiar: the exponential coefficient strongly depends on doping level.
No consensus has been reached so far on the origin of the isotope effect in the
cuprates. Here we show that the oxygen isotope effect in cuprates is in
agreement with the bisoliton theory of superconductivity.Comment: 3 pages including 4 figures; version 2 is with minor correction
The Structure of Martian Magnetosphere at the Dayside Terminator Region as Observed on MAVEN Spacecraft
We analyzed 44 passes of the MAVEN spacecraft through the magnetosphere,
arranged by the angle between electric field vector and the projection of
spacecraft position radius vector in the YZ plane in MSE coordinate system
( E ). All passes were divided into 3 angular sectors near 0{\deg},
90{\deg} and 180{\deg} E angles in order to estimate the role of IMF
direction in plasma and magnetic properties of dayside Martian magnetosphere.
The time interval chosen was from January 17 through February 4, 2016 when
MAVEN was crossing the dayside magnetosphere at SZA ~ 70{\deg}. Magnetosphere
as the region with prevailing energetic planetary ions is always found between
the magnetosheath and the ionosphere. 3 angular sectors of dayside interaction
region in MSE coordinate system with different orientation of the solar wind
electric field vector E = -1/c V x B showed that for each sector one can find
specific profiles of the magnetosheath, the magnetic barrier and the
magnetosphere. Plume ions originate in the northern MSE sector where motion
electric field is directed from the planet. This electric field ejects
magnetospheric ions leading to dilution of magnetospheric heavy ions
population, and this effect is seen in some magnetospheric profiles. Magnetic
barrier forms in front of the magnetosphere, and relative magnetic field
magnitudes in these two domains vary. The average height of the boundary with
ionosphere is ~530 km and the average height of the magnetopause is ~730 km. We
discuss the implications of the observed magnetosphere structure to the
planetary ions loss mechanism.Comment: 24 pages, 13 figure
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