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1.
P. A. Prudkovskiĭ 《JETP Letters》2008,86(10):652-656
The process of the domain-block structure formation at the ferroelectric phase transition in KDP-type crystals is investigated. An effective Hamiltonian of the system is constructed; the growth of domain blocks in the vicinity of the Curie point is numerically simulated using the Monte Carlo method, and the temperature interval of the domain block growth is determined. It is shown that the asymptotic dependence of the mean block size on time has the form R(t) ~ √t/lnt. In the framework of an equivalent mathematical model combining the Ising and Kosterlitz-Thouless two-dimensional models, a kinetic equation that approximately describes the evolution of the domain-block size distribution function is derived. 相似文献
2.
New experimental data on fluctuations in the multiplicities of negatively charged particles in interactions of light nuclei
(p, d, 4He, 12C) with carbon nuclei at a momentum of 4.2 A GeV/c in 4π geometry are reported. The data indicate a behavior similar to that earlier observed by the NA49 Collaboration. The
cascade evaporation model, FRITIOF model, and UrQMD 1.3 model are used to analyze the data. The dependence of the fluctuations
on nuclear collision centrality is theoretically described without any exotic assumptions. According to the FRITIOF model,
the dependence of the multiplicity fluctuations on the collision centrality is to a large extent governed by fluctuations
in the number of “wounded” nucleons that are associated with the experimental observation conditions. The NA49 Collaboration
data are also described.
Original Russian Text ? A.S. Galoyan, E.N. Kladnitskaya, V.V. Uzhinsky, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ
i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 10, pp. 718–721. 相似文献
3.
Extremely high values of the relative permittivity up to 107 and the magnetocapacitance up to 105% have been found in La1 − x
Sr
x
MnO3 single crystals (x = 0.1, 0.11). These phenomena are observed even at room temperature. The observed behavior can be a consequence of the strong
interaction among charge, spin, and lattice degrees of freedom, which leads to charge and phase separation in the regime before
the percolation threshold.
Original Russian Text ? R.F. Mamin, T. Egami, Z. Marton, C.A. Migachev, M.F. Sadykov, 2007, published in Pis’ma v Zhurnal
éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 10, pp. 731–735. 相似文献
4.
《JETP Letters》2005,82(12):743-747
The cross section for the process e
+
e
− → π+π− is measured in the c.m. energy range 1.04—1.38 GeV by analyzing 995 000 selected collinear events including 860000 e
+
e
− events, 82000 μ+μ− events, and 33000 π+π− events. The systematic and statistical errors of measuring the pion form factor are equal to 1.2–4.2 and 5–13%, respectively.
__________
Translated from Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, Vol. 82, No. 12, 2005, pp. 841–845.
Original Russian Text Copyright ? 2005 by Aul’chenko, Akhmetshin, Banzarov, Barkov, Bashtovoĭ, Bondarev, Bondar’, Bragin,
Valishev, Gabyshev, Gorbachev, Grebenyuk, Grigor’ev, Dhawan, Epifanov, Zaĭtsev, Zverev, Ignatov, Kazanin, Karpov, Koop, Krokovny,
Kuz’min, Logashenko, Lukin, Lysenko, Mil’shteĭn, Mikhaĭlov, Nesterenko, Nikulin, Otboev, Okhapkin, Perevedentsev, Polunin,
Popov, Redin, Roberts, Root, Ruban, Ryskulov, Sibidanov, Sidorov, Skrinsky, Smakhtin, Snopkov, Solodov, Thompson, Fedotovich,
Khazin, Hughes, Shamov, Shatunov, Shwartz, éĭdel’man, Yudin.
Deceased. 相似文献
5.
The results of experimental and theoretical investigations of the electromagnetically induced transparency regime on the 4
I
9/2-4
G
5/2 transition in Nd3+ ions doped in LaF3 are presented. The superhyperfine splitting of the upper and lower working levels has been determined on the basis of the
results obtained. A theoretical model adequately describing the parameters of the resonances of electromagnetically induced
transparency has been developed by analyzing the experimental data.
Original Russian Text ? R.A. Akhmedzhanov, A.A. Bondartsev, L.A. Gushchin, N.A. Zharova, 2007, published in Pis’ma v Zhurnal
éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 9, pp. 646–650. 相似文献
6.
The concept of P-quasispin is used as a framework for developing a formalism for polarization transformation by means of lossless polarization-changing
optical elements for both classical and quantum multimode light fields. As an example, a classification of transformations
of this kind is presented for two-mode biphoton fields that implement the information-theoretic concepts of qutrit and ququart
(quantum systems in three-and four-dimensional Hilbert states, respectively).
Original Russian Text ? V.P. Karassiov, S.P. Kulik, 2007, published in Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki,
2007, Vol. 131, No. 1, pp. 37–53. 相似文献
7.
N. E. Sluchanko D. N. Sluchanko V. V. Glushkov S. V. Demishev N. A. Samarin N. Yu. Shitsevalova 《JETP Letters》2007,86(9):604-607
Within a wide temperature range of 1.8–300 K, the Hall effect in holmium dodecaboride is investigated. The measurements of
the angular dependences of the Hall resistance ρH(φ, T, H) for HoB12 performed in a high magnetic field up to 80 kOe at helium and intermediate temperatures made it possible to separate the
normal and anomalous contributions to the Hall effect. Analysis of the anomalous component behavior in the paramagnetic and
Néel phases suggests the appearance of the 5d-state magnetic polarization (the spin polaron effect) and makes it possible to compare the revealed features of the Hall
coefficient R
H(T, H) with the H-T magnetic phase diagram of HoB12.
Original Russian Text ? N.E. Sluchanko, D.N. Sluchanko, V.V. Glushkov, S.V. Demishev, N.A. Samarin, N.Yu. Shitsevalova, 2007,
published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 9, pp. 691–694. 相似文献
8.
S. F. Dubinin S. G. Teploukhov V. E. Arkhipov V. D. Parkhomenko é. A. Nefeld A. V. Korolev N. A. Ugryumova Ya. M. Mukovski 《Physics of the Solid State》2007,49(4):739-745
The structural and magnetic states of Pr1−x
Sr
x
MnO3 (x = 0.22, 0.24) manganite crystals were studied over a wide temperature range. Measurements of the magnetic susceptibility
and electrical resistivity demonstrated that these manganites belong to the class of ferromagnetic semiconductors. Thermal
neutron elastic scattering patterns revealed that, in the temperature range 4.2–350 K, the manganites have an orthorhombic
structure (space group Pnma) with a well-pronounced cooperative Jahn-Teller effect. Major emphasis was placed on the nuclear magnetic superstructure
with a wave vector q = (2π/2a, 0, 2π/2c). It was shown that this superstructure suggests 1/4-type charge ordering in the manganites under investigation.
Original Russian Text ? S.F. Dubinin, S.G. Teploukhov, V.E. Arkhipov, V.D. Parkhomenko, é.A. Neĭfel’d, A.V. Korolev, N.A.
Ugryumova, Ya.M. Mukovskiĭ, 2007, published in Fizika Tverdogo Tela, 2007, Vol. 49, No. 4, pp. 704–710. 相似文献
9.
The effect of high pressure on the crystal structure of the intermetallic compounds R2Fe17 − x
Six (R = Lu or Y; x = 0 or 1.7) was studied using neutron diffraction. A correlation between changes in structural parameters and magnetic properties
under the action of high pressure, as well as under chemical substitution of Si for Fe atoms, was analyzed in terms of localized
moment and spin fluctuation models. The spin fluctuation model was found to describe more adequately the experimentally observed
increase in the Curie temperature upon chemical substitution and the decrease in this temperature under the action of high
pressure. Possible reasons for the suppression of a collinear ferromagnetic state and the occurrence of a noncollinear antiferromagnetic
state in R2Fe17−x
Six under pressure are discussed based on estimated differences between the total energy minima of these states.
Original Russian Text ? D.P. Kozlenko, V.I. Voronin, V.P. Glazkov, B.N. Savenko, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ
i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 9, pp. 675–680. 相似文献
10.
Spectral dependences of the relative permittivity ɛ = ɛ1 − iɛ2 of a uniaxial weak ferromagnet FeBO3 are measured for two principal polarizations in the energy range 0.6–5.6 eV. The positions have been determined for the charge-transfer
transitions that make the main contribution to absorption above the bandgap and determine the refractive-index dispersion
below the bandgap. The isotropic magnetic contribution to the refractive index has been detected by studying the temperature
dependence of the refractive index in the range 100–700 K; its value (≈2 × 10−2) is found to be record high for magnetic dielectrics. The energy shift of the effective oscillator, which characterizes the
shift of the positions of the charge-transfer transitions due to magnetic ordering, is determined from these data within the
framework of a single-oscillator model. The value of the exchange striction in FeBO3 is determined from optical measurements.
Original Russian Text ? P.A. Markovin, A.M. Kalashnikova, R.V. Pisarev, Th. Rasing, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ
i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 11, pp. 822–827. 相似文献
11.
The properties of a capacitive HF discharge with growing nanoparticles are studied with the use of kinetic PIC-MCC simulation.
At the initial stage of growth, the nanoparticles are shown to be localized at the interface between the near-electrode layer
and quasi-neutral plasma, where the rate of ionization by electron impact has the maximum value. At the beginning of formation
of particles, plasma parameters change rapidly and a transition between the capacitive and spatial discharge burning modes
is observed for a certain critical size of the particles. If the growth of the dust particles continues, their distribution
over the discharge becomes more uniform and the steady-state parameters of the gas-discharge plasma hardly change.
Original Russian Text ? I.V. Shveigert, F.M. Peeters, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ
Fiziki, 2007, Vol. 86, No. 9, pp. 657–661. 相似文献
12.
In YBa2Cu3O7 − x
films grown on sapphire bicrystal substrates, the Josephson junctions are prepared based on artificial grain boundaries formed
by the turn of the crystal lattices about the [100] axis. The films are deposited by the laser ablation method on the buffer
CeO2 layer. The critical film temperature reaches 88.5 K with a transition width of 1.5 K. Junctions from 2 to 3-μ m wide are
integrated into the planar log-periodic antennas and their characteristics are measured at 77 K. The characteristic voltage
I
c
R
n
reaches 570 μV. With exposure to external radiation at a frequency of 113 GHz, the Shapiro steps were observed on the current-voltage
characteristic. The temperature sensitivity of this detector placed in a quasi-optical receiving unit is measured. At the
modulation of the input radiation temperature 77 K/300 K, a response of more than 200 nV is observed at the detector output.
At the modulation frequency, intrinsic noise is about 1 nV/Hz1/2, which corresponds to a temperature resolution of 1 K.
Original Russian Text ? M. Tarasov, E. Stepantsov, A. Kalabukhov, M. Kupriyanov, D. Winkler, 2007, published in Pis’ma v Zhurnal
éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 11, pp. 828–831. 相似文献
13.
The monoclinic (space group C2/m) superstructure of V14O6, which is formed in the atom-vacancy ordering of the tetragonal solid solution of oxygen in vanadium, is studied by the methods
of x-ray diffraction and symmetry analysis. It has been found that the channel of the order-disorder phase transition attributed
to the formation of the monoclinic suboxide V14O6 includes six superstructure vectors belonging to three non-Lifshitz stars {k
1−1}, {k
1−2}, and {k
1–3} of one type {k
1}. The distribution function of the O atoms in the V14O6 monoclinic superstructure has been calculated. It has been shown that the displacements of V atoms distort the body-centered
tetragonal metal sublattice, thus preparing the formation of the fcc sublattice and the transition from the suboxide V14O6 to the cubic vanadium monoxide with the B1 structure.
Original Russian Text ? A.I. Gusev, D.A. Davydov, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki,
2007, Vol. 86, No. 10, pp. 746–751. 相似文献
14.
The differential energy spectrum of cosmic rays that is obtained on the basis of the measurements of Cherenkov radiation from
extensive air showers in an energy range of 1015–1020 eV is compared with the model of the propagation of primary particles in the interstellar medium with fractal properties.
It is found that the shape of the experimental spectrum is in good agreement with the shape of the calculated spectrum of
“all particles” at 1015–1018 eV. The average mass composition of cosmic rays that is calculated on the basis of five components does not contradict the
average mass composition obtained from the experimental data for several parameters in this energy range.
Original Russian Text ? S.P. Knurenko, A.A. Ivanov, A.V. Saburov, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i
Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 10, pp. 709–712. 相似文献
15.
E. Kh. Mukhamedzhanov M. M. Borisov A. N. Morkovin A. A. Antonenko A. P. Oreshko E. N. Ovchinnikova V. E. Dmitrienko 《JETP Letters》2007,86(12):783-787
The 222 and 600 reflections near the germanium absorption K edge were studied on the Kurchatov synchrotron radiation source. The energy spectrum of the 222 reflection is caused by the
interference of the weak nonresonant and purely resonant contributions to the tensor atomic factor, whereas the 600 reflection
is purely resonant. The energy dependence of the magnitude and phase of the resonant contribution to the scattering amplitude
was determined from a change in the interference pattern. The numerical simulation of the energy spectra of reflections with
the inclusion of the dipole-quadrupole and thermally induced contributions shows that the latter is dominant at room temperature.
Original Russian Text ? E.Kh. Mukhamedzhanov, M.M. Borisov, A.N. Morkovin, A.A. Antonenko, A.P. Oreshko, E.N. Ovchinnikova,
V.E. Dmitrienko, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 12, pp.
896–900. 相似文献
16.
Effect of spin fluctuations on the superconducting phase of Hubbard fermions in the t-t′-t″-J* model
The effect of spin-fluctuation scattering processes on the region of the superconducting phase in strongly correlated electrons (Hubbard fermions) is investigated by the diagram technique for Hubbard operators. Modified Gor’kov equations in the form of an infinitely large system of integral equations are derived taking into account contributions of anomalous components $ P_{0\sigma ,\bar \sigma 0} The effect of spin-fluctuation scattering processes on the region of the superconducting phase in strongly correlated electrons
(Hubbard fermions) is investigated by the diagram technique for Hubbard operators. Modified Gor’kov equations in the form
of an infinitely large system of integral equations are derived taking into account contributions of anomalous components
of strength operator . It is shown that spinfluctuation scattering processes in the one-loop approximation for the t-t′-t″-J* model taking into account long-range hoppings and three-center interactions are reflected by normal (P
0σ, 0σ) and anomalous () components of the strength operator. Three-center interactions result in different renormalizations of the kernels of the
integral equations for the superconducting d phase in the expressions for the self-energy and strength operators. In this approximation for the d-type symmetry of the order parameter for the superconducting phase, the system of integral equations is reduced to a system
of nonhomogeneous equations for amplitudes. The resultant dependences of critical temperature on the electron concentrations
show that joint effect of long-range hoppings, three-center interactions, and spin-fluctuation processes leads to strong renormalization
of the superconducting phase region.
Original Russian Text ? V.V. Val’kov, A.A. Golovnya, 2008, published in Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki,
2008, Vol. 134, No. 6, pp. 1167–1180. 相似文献
17.
Alessandro Torcini Paolo Politi 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,25(4):519-529
Surface growth models may give rise to instabilities with mound formation whose typical linear size L increases with time (coarsening process). In one dimensional systems coarsening is generally driven by an attractive interaction
between domain walls or kinks. This picture applies to growth models for which the largest surface slope remains constant
in time (corresponding to model B of dynamics): coarsening is known to be logarithmic in the absence of noise ( L(t) ∼ ln t) and to follow a power law ( L(t) ∼t
1/3) when noise is present. If the surface slope increases indefinitely, the deterministic equation looks like a modified Cahn-Hilliard
equation: here we study the late stages of coarsening through a linear stability analysis of the stationary periodic configurations
and through a direct numerical integration. Analytical and numerical results agree with regard to the conclusion that steepening
of mounds makes deterministic coarsening faster : if α is the exponent describing the steepening of the maximal slope M of mounds ( M
α∼L) we find that L(t) ∼t
n: n is equal to for 1≤α≤2 and it decreases from to for α≥2, according to n = α/(5α - 2). On the other side, the numerical solution of the corresponding stochastic equation clearly shows that in the
presence of shot noise steepening of mounds makes coarsening slower than in model B: L(t) ∼t
1/4, irrespectively of α. Finally, the presence of a symmetry breaking term is shown not to modify the coarsening law of model
α = 1, both in the absence and in the presence of noise.
Received 28 September 2001 and Received in final form 21 November 2001 相似文献
18.
Measurement of the e+e? → π+π? cross section with the CMD-2 detector in the 370–520-MeV energy range
《JETP Letters》2006,84(8):413-417
The results of the experiment on the measurement of the e
+
e
− → π+π− cross section in a cm energy range of 370–520 MeV are presented. The systematic measurement error is equal to 0.7%. In the
vector dominance model, the pion electromagnetic radius is calculated using all the CMD-2 data on the pion form factor. The
cross section for the production of a muon pair is measured in the energy range of the experiment.
Original Russian Text ? V.M. Aul’chenko, R.R. Akhmetshin, V.Sh. Banzarov, L.M. Barkov, N.S. Bashtovoĭ, D.V. Bondarev, A.E.
Bondar’, A.V. Bragin, N.I. Gabyshev, D.A. Gorbachev, A.A. Grebenyuk, D.N. Grigor’ev, S.K. Dhawan, D.A. Epifanov, A.S. Zaĭtsev,
S.G. Zverev, F.V. Ignatov, V.F. Kazanin, S.V. Karpov, I.A. Koop, P.P. Krokovny, A.S. Kuz’min, I.B. Logashenko, P.A. Lukin,
A.P. Lysenko, A.I. Mil’shteĭn, K.Yu. Mikhaĭlov, I.N. Nesterenko, M.A. Nikulin, A.V. Otboev, V.S. Okhapkin, E.A. Perevedentsev,
A.S. Popov, S.I. Redin, B.L. Roberts, N.I. Root, A.A. Ruban, N.M. Ryskulov, A.L. Sibidanov, V.A. Sidorov, A.N. Skrinsky, V.P.
Smakhtin, I.G. Snopkov, E.P. Solodov, J.A. Thompson, G.V. Fedotovich, B.I. Khazin, V.W. Hughes, A.G. Shamov, Yu.M. Shatunov,
B.A. Shvarts, S.I. éĭdel’man, Yu.V. Yudin, 2006, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki,
2006, Vol. 84, No. 8, pp. 491–495. 相似文献
19.
A new scheme is proposed for proton and light-ion acceleration to relativistic energies by superstrong laser radiation interacting
with a structured plasma target. The proposal consists in the use of two-component targets consisting of heavy and light ions,
where an ambipolar field is formed under the action of the ponderomotive force of incident radiation, and, in contrast to
the traditional schemes, acceleration starts from the front boundary of the layer. It is shown that, for the optimized target
parameters, monoenergetic GeV ion beams can be produced for radiation pulse intensities on the order of 1021−1022 W/cm2.
Original Russian Text ? A.V. Korzhimanov, A.A. Gonoskov, A.V. Kim, A.M. Sergeev, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ
i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 9, pp. 662–669. 相似文献
20.
M. V. Yakunin S. M. Podgornykh V. N. Neverov 《Journal of Experimental and Theoretical Physics》2007,105(1):214-222
A procedure is proposed for precise scanning of the (B
⊥, B
‖) plane between the magnetic field projections that are perpendicular and parallel to (quasi-)two-dimensional layers when
measuring their longitudinal and Hall magnetoresistances. Investigations of a n-In
x
Ga1−x
As/GaAs double quantum well (x ≈ 0.2) performed using this procedure make it possible to reveal a number of the features of the magnetoresistance, which
appear due to a complex energy spectrum of the double quantum well in a parallel field, and to separate them from the structures
associated with the magnetic breakdown. The trajectories representing the features of the magnetoresistance in the (B
⊥, B
‖) plane are described by the semiclassical calculations of the quantization of the energy spectrum of the double quantum well
under the action of the perpendicular field component. The structures appearing due to the magnetic breakdown are amplified
with increasing the total magnetic field magnitude and, in the samples with low mobility, completely suppress the features
caused by the motion of an electron with a constant pseudospin component. The peaks corresponding to the magnetic breakdown
are split in a strong parallel field due to the spin splitting of the Landau levels. These splittings correspond to the effective
Landé factor |g*| ≈ 3.
Original Russian Text ? M.V. Yakunin, S.M. Podgornykh, V.N. Neverov, 2007, published in Zhurnal éksperimental’noĭ i Teoreticheskoĭ
Fiziki, 2007, Vol. 132, No. 1, pp. 241–249. 相似文献