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1.
It is shown in numerical simulations with two-level atoms moving through a single-mode high-Q cavity that spontaneous emission of a new type — chaotic Rabi vacuum oscillations — arises in the strong atom-field coupling
regime.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 11, 801–806 (10 June 1997) 相似文献
2.
V. M. Shmelev A. D. Margolin N. Ya. Vasilik V. G. Krupkin V. T. Volov D. B. Volov 《Technical Physics》1998,43(9):1069-1071
An alternative, nonelectrical method for obtaining a dense radiating plasma and the possibilities of using this method to
pump solid-state lasers are investigated. The plasma was obtained experimentally by heating the working gas in a two-stage
ballistic plasmatron. A new device — a vortex chamber — is proposed for transferring energy into the plasmatron-laser system.
Zh. Tekh. Fiz. 68, 67–70 (September 1998) 相似文献
3.
A. V. Balakin V. A. Bushuev B. I. Mantsyzov P. Masselin I. A. Ozheredov A. P. Shkurinov D. Boucher 《JETP Letters》1999,70(11):725-729
A new property of a one-dimensional periodic structure — amplification of the sum-frequency signal arising under the simultaneous
action of two laser pulses on this structure with radiation frequencies corresponding to the edges of the fixed Bragg band
gap — is experimentally observed and described.
Pis’ma Zh. éksp. Teor. Fiz. 70, No. 11, 718–721 (10 December 1999) 相似文献
4.
Over the last ten years interest in the physics of de Sitter space—time has been growing very fast. Besides the supposed existence
of a “de Sitterian period” in inflation theories, the observational evidence of an acceleration of the universe expansion
(interpreted as a positive cosmological constant or a “dark energy” or some form of “quintessence”) has triggered a lot of
attention in the physics community. A specific de Sitterian field called “massless minimally coupled field” (mmc) plays a
fundamental role in inflation models and in the construction of the de Sitterian gravitational field. A covariant quantization
of the mmc field, à la Krein—Gupta—Bleuler was proposed in Class. Quantum. Grav. 17, 1415 (2000). In this talk, we will review this construction and explain the relevance of such a field in the construction
of a massless spin-2 field in de Sitter space—time. 相似文献
5.
T. D. Varfolomeeva S. V. Popova A. G. Lyapin V. V. Brazhkin S. G. Lyapin Yu. P. Kudryavtsev S. E. Evsyukov 《JETP Letters》1997,66(4):255-260
Structural transformations of the cumulene form of amorphous carbyne which are induced by heating at high pressure (7.7 GPa)
are investigated. These can be described by the sequence amorphous phase — crystal — amorphous phase — disordered graphite.
Raman scattering shows that predominately the chain structure of carbyne remains at the first three stages. It was found that
the intermediate crystalline phase is an unknown modification of carbon whose structure is identified as cubic (a=3.145 Å). A mechanism of structural transformations in carbyne that involves the formation of new covalent bonds between
chains is discussed.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 4, 237–242 (25 August 1997) 相似文献
6.
N. S. Ginzburg I. V. Zotova I. V. Konoplev A. S. Sergeev V. G. Shpak S. A. Shunailov M. R. Ul’maskulov M. I. Yalandin 《JETP Letters》1996,63(5):331-335
Intense (several hundreds of kilowatts) subnanosecond coherent microwave radiation — cyclotron superradiance of an electron
swarm moving in a uniform magnetic field — was recorded. The maximum power of the radiation was observed under group synchronization
conditions, when the translational velocity of the swarm is equal to the group velocity of the waves in the waveguide channel.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 5, 322–325 (10 March 1996) 相似文献
7.
V. A. Burdov 《JETP Letters》1999,70(6):390-395
It is shown that when a strong ac electric field acts on an electron in a double quantum well, the dipole moment is an almost
periodic function of the dc voltage applied to the structure. An antipolarization effect — the structure is polarized in a
direction opposite to the external field — appears during one half of the period.
Pis’ma Zh. éksp. Teor. Fiz. 70, No. 6, 386–391 (25 September 1999) 相似文献
8.
A model of a ferromagnet with nonuniform dissipation is introduced for the Landau-Lifshitz equations. It is shown that in
this model a ferromagnet can be regarded as an oscillating active medium where the formation of autowave structures — spin
autowaves, pacemakers, and spiral waves — is possible. Their wave characteristics, expressed in terms of the parameters of
the medium, are found for a special case.
Fiz. Tverd. Tela (St. Petersburg) 39, 513–515 (March 1997) 相似文献
9.
A replacement of the adsorbate in porous silicon is carried out in ultra-high vacuum. The photoluminescence line is shifted
and quenched as the products of anodization of silicon — silicon hydrides and atomic and molecular hydrogen — undergo thermal
decomposition and desorption. Adsorption of molecular chlorine restores the 560 nm photoluminescence band, which we identified
as radiation from graphite nanoparticles.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 2, 106–111 (25 January 1996) 相似文献
10.
A. S. Moskvin I. B. Krynetskii R. Shimchak Yu. D. Panov S. V. Naumov A. A. Samokhvalov 《Physics of the Solid State》1997,39(3):412-418
It is shown that the formation of tunnel paramagnetic centers — triplet spin centers with a strongly different adiabatic potential
in different spin states — can form in copper oxides based on CuO clusters. The results of measurements of the magnetization
and magnetostriction of CuO single crystals are reported. They attest to the presence of nonequilibrium spin states and confirm
the results obtained in the model of tunnel paramagnetic centers.
Fiz. Tverd. Tela (St. Petersburg) 39, 474–482 (March 1997) 相似文献
11.
V. A. Saranin 《Technical Physics》1998,43(2):145-150
The behavior of droplets in the atmosphere in an electric field has important bearing on the theory of thunderstorms. One
of the possible mechanisms by which droplets become charged—the induction mechanism in the presence of nonuniform evaporation—is
investigated in greater detail on the basis of recent experimental results (V. A. Saranin, Zh. Tekh. Fiz. 65(6), 21 (1995) [Tech. Phys. 40, 332 (1995)]).
Zh. Tekh. Fiz. 68, 16–21 (February 1998) 相似文献
12.
The Raman interaction of optical fields with a Bose condensate is studied in the adiabatic regime. A superposition of operators
is found — one annihilating an atom in a metastable state and the other annihilating a photon in resonance with a transition
from the ground state to an excited state — which is an adiabatic invariant of the problem (Raman polariton). Possible applications
for Bose-condensate diagnostics and development of atomic lasers are proposed.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 7, 473–477 (10 October 1996) 相似文献
13.
A new effect — the splitting of the tips (branching) of a microwave streamer arising from a pre-existing dense plasma cloud
in an above-threshold electric field — is obtained numerically on the basis of a planar two-dimensional model. The causes
of this phenomenon and the factors suppressing it are found. An expression is obtained for the value of the cloud radius above
which branching occurs.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 1, 15–19 (10 January 1999) 相似文献
14.
We present evidence for a thermodynamically stable incommensurate elongated-triangle (ELT) phase in quartz, observed by transmission
electron microscopy at the α-β structural transition. The phase sequence on cooling is: incommensurate equilateral-triangle
(EQT) phase (ferroelectric)—incommensurate ELT (ferroelectric and ferroelastic)— uniform α phase. The ELT blocks could be
responsible for the large light scattering in the vicinity of the α-gb transition.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 5, 376–381 (10 September 1996)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
15.
V. V. Vecheslavov 《JETP Letters》1996,63(12):1047-1053
A new effect [V. V. Vecheslavov, Zh. éksp. Teor. Fiz. 109, 2208 (1996) (JETP 82, 1190 (1996)]—the appearance of low-frequency secondary harmonics in the separatrix mapping of a system—is discussed in detail
for the example of a pendulum with a two-frequency perturbation. It is shown that there exist regions of values of the perturbation
parameters where these harmonics make the main contribution to the formation of the chaotic layer of the fundamental resonance.
The results of analytical and numerical determinations of the amplitudes of the secondary harmonics are compared.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 12, 989–994 (25 June 1996) 相似文献
16.
The points of lithium fluoride needles are investigated by laser photoelectronic projection microscopy. A situation in which
a single atomic-size source of electrons — an F
2 color center — is observed in the region near the point is realized. As a result of the good fluorescence properties of these
centers, these needles can be used as the active element of a scanning fluorescence microscope employing resonance transfer
of electronic excitation energy.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 6, 441–444 (25 March 1997) 相似文献
17.
For fields above a critical value the expansion of the conductivity in powers of the field ceases to be valid and the weak-nonlinearity
approximation no longer works. The density behavior of the critical fields in strongly inhomogeneous media near the percolation
threshold is found on the basis of two criteria—an average criterion and a local criterion. The parameter values of the medium
for which crossover—a change of the critical behavior—occurs are determined. Similar calculations are performed for the critical
currents.
Zh. Tekh. Fiz. 68, 5–8 (June 1998) 相似文献
18.
A new phenomenon — intense luminescence of noncolored lithium fluoride (LiF) crystals excited by an electrodeless pulsed microwave
discharge at the prebreakdown stage of development — is observed. This luminescence consists of the luminescence of short-lived
aggregate F2 and F
3
+
color centers at room temperature. It is shown that the density of short-lived color centers induced in the surface layer
of LiF crystals by a microsecond microwave discharge reaches values of ∼1019−1020 cm−3.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 3, 163–167 (10 August 1997) 相似文献
19.
Molecular-dynamics was used to investigate the structural changes occurring in a three-dimensional solid when the solid is
transferred from an amorphous into a crystalline state. Crystal cells of a new type — pentadecahedrons with five square lateral
faces and ten regular triangular faces at the vertices of a cell — were found for the first time in a computer experiment.
It is shown that a bistructure consisting of crystal cells of different types, including cells with five-fold symmetry axes,
are stable in the solid.
Fiz. Tverd. Tela (St. Petersburg) 40, 1919–1924 (October 1998) 相似文献
20.
A new protocol is proposed for quantum cryptography. The protocol is based on the use of a set of measurements which make
it possible to reconstruct completely the density matrix — the information carrier — of a physical system. Such a protocol
can be implemented by means of homodyne detection (well known in quantum optics) of an electromagnetic field. An example is
given of a quantum cryptosystem in which the vacuum state of the photon field is used as one of two information states.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 1, 64–68 (10 July 1997) 相似文献