共查询到20条相似文献,搜索用时 15 毫秒
1.
Grishin M. V. Dalidchik F. I. Kovalevskii S. A. Kolchenko N. N. Shub B. R. 《JETP Letters》1997,66(1):37-40
The vibrational frequencies of adsorbed H2O and D2O molecules are measured under high-vacuum conditions by in-cavity scanning tunneling spectroscopy. An isotope effect is observed.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 1, 37–39 (10 July 1997) 相似文献
2.
I. I. Sadykov 《JETP Letters》1997,66(2):114-119
Crossed dc and ac magnetic fields are applied to a paramagnet in a continuous regime in an investigation of the induction
signal at the doubled and tripled pump frequencies. The experimental object is powdered diphenyl picryl hydrazyl (DPPH), and
the pump frequency used is 11 MHz. It is shown that harmonic generation and the orientational dependences of the harmonics
arise due to nonlinear variations of the magnitude and the “rocking” angle of the vector sum of the external fields and the
precession frequency of the spin magnetization. Anomalies are observed in the Bloch-Siegert effect.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 2, 104–109 (25 July 1997) 相似文献
3.
V. M. Svistunov V. Yu. Tarenkov A. I. D’yachenko R. Aoki 《Physics of the Solid State》1997,39(10):1572-1574
Pronounced softening of the high-frequency part of the phonon spectrum at high pressures is observed by means of tunneling
spectroscopy. As the pressure is increased, the characteristic frequencies of the spectrum at ħΩ>60 mV decrease at the rate d ln(ħΩ)/dP≈(−6.5±0.5)×10−3 kbar−1. On the other hand, hydrostatic pressure causes the low frequencies of the phonon spectrum of Bi 2223 metal oxide to shift
very slightly toward higher energies, consistent with Raman spectra.
Fiz. Tverd. Tela (St. Petersburg) 39, 1764–1766 (October 1997) 相似文献
4.
It is observed that in single-crystalline yttrium iron garnet the amplitude of characteristic flexural oscillations of a 180°
domain wall containing Bloch lines increases sharply when drift of the Bloch lines is excited. The resonance frequencies of
these oscillations are virtually identical to those of flexural oscillations of a monopolar wall. It is shown experimentally
that this phenomenon is most likely caused by a magnetic aftereffect.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 1, 72–75 (10 January 1998) 相似文献
5.
A. V. Pronin B. P. Gorshunov A. A. Volkov H. S. Somal D. van der Marel B. J. Feenstra Y. Jaccard J. -P. Locquet 《JETP Letters》1998,68(5):432-436
Direct measurements of the complex conductivity spectra of thin-film La2−2x
SrxCuO4 are made at frequencies of 5–40 cm−1. Narrow, intense Drude-type excitation is observed in the superconducting phase.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 5, 406–409 (10 September 1998) 相似文献
6.
The conservation of magnetic flux in the evolution and collapse of massive stars suggests that Alfvén magnetoplasma oscillations
can be excited in an isolated neutron star by residual (after the supernova explosion) disturbances of the magnetized electron-nuclear
plasma localized in the peripheral crust of the star. The frequencies of the poloidal Alfvén oscillations are calculated in
the uniform magnetic field approximation, and it is found that the periods of the oscillations fall into the time interval
of the periodicity of radio pulsar radiation. This coincidence of the periods could mean that, at least for some pulsars observed
in the radio range, the electromagnetic activity is due to converstion of the energy of magnetoplasma oscillations into electromagnetic
radiation.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 9, 593–598 (10 November 1996) 相似文献
7.
M. E. Kompan E. G. Kuz’minov V. B. Kulik I. I. Novak V. I. Beklemyshev 《JETP Letters》1996,64(10):748-753
An experiment on Raman scattering in porous silicon containing a regular system of quantum wires reveals a shift of the phonon
frequencies of the silicon lattice toward higher energies. The effect is interpreted as a manifestation of a compressed state
of the material in the quantum wires. It is shown that the observed deformation plays a large role in the formation of the
structure of porous silicon.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 10, 695–700 (25 November 1996) 相似文献
8.
The possibility of resonance during elastic intravalley scattering in n-type semiconductors is investigated in connection with the crossing (due to anisotropy of the effective mass) of the energy
levels of excited states of a shallow donor as functions of the magnetic field. The hybridization of states of different frequencies
in the vicinity of a crossing is attributed to the emergence of a nonzero dipole moment of the excited impurity atom and,
accordingly, a long-range potential, which creates carrier-transport anomalies. The lower part of the donor spectrum is calculated
as a function of the magnetic field in Si with B∥〈001〉 and in Ge with B∥〈111〉 or B∥〈110〉. A crossing occurs in Ge in the field range 9.9 T<B<16.7 T and in Si in the field range 10.5 T<B<37.7 T. The characteristic longitudinal relaxation time and the transverse conductivity, which are determined by scattering
at excited donors in the presence of the hybridization of states, are calculated.
Zh. éksp. Teor. Fiz. 112, 975–1010 (September 1997) 相似文献
9.
Dynamic self-organization of magnetic domains is observed in amorphous gadolinium-cobalt films in narrow temperature intervals
on both sides of the magnetic compensation point. Spiral dynamic domains form in a limited range of ac magnetic field amplitudes
and frequencies.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 11, 688–692 (10 December 1997) 相似文献
10.
We have performed experiments in which self-generation of dark envelope solitons for spin waves at microwave frequencies were
obtained. Stable self-generation of dark solitons was observed in a ring consisting of tangentially magnetized yttrium iron
garnet film and a microwave signal amplifier.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 3, 229–233 (10 August 1998) 相似文献
11.
Unusual spin-precession states of 3He-B in which the magnetization is half the equilibrium value are investigated by continuous-wave NMR methods. Signals at
frequencies equal to 1/2 and 3/2 of the magnetization precession frequency are observed in two such states. Such signals exist
because the order parameter of superfluid 3He in these states precesses with frequency equal to half the magnetization precession frequency.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 3, 200–205 (10 February 1999) 相似文献
12.
P. A. Prudkovskii O. V. Skugarevskii A. N. Penin 《Journal of Experimental and Theoretical Physics》1997,85(4):812-817
An amplification of the intensity of pump oscillations is observed experimentally at frequencies from 100 Hz to 1 kHz during
photoinduced light scattering and holographic-type parametric scattering in photorefractive lithium tantalate and niobate.
Possible ways are analyzed for explaining the existence of a photorefractive response in these crystals over times of 10−2–10−3 s, which are five orders of magnitude shorter than the Maxwell time.
Zh. éksp. Teor. Fiz. 112, 1490–1498 (October 1997) 相似文献
13.
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
14.
The ion current of adsorbed water molecules is studied experimentally as a function of the frequency of near-IR radiation
incident on a surface at frequencies in the intrinsic vibrational bands of the water molecule. The ions are produced by nonequilibrium
field surface ionization. The observed band (near one of the combination frequencies) has a width of 100 cm−1 and is shifted relative to the free molecular band by 130 cm−1. Estimates show that the cross section for absorption of the radiation by the adsorbed molecules is 3–4 orders of magnitude
larger than for free molecules, as is typical of surface processes.
Zh. Tekh. Fiz. 69, 123–127 (September 1999) 相似文献
15.
Kh. G. Bogdanova V. A. Golenishchev-Kutuzov V. E. Leont’ev M. R. Nazipov M. M. Shakirzyanov M. I. Kurkin V. V. Nikolaev 《Journal of Experimental and Theoretical Physics》1997,85(5):1001-1006
Ultrasound damping at T=4.2 K in single crystal easy-plane antiferromagnetic KMnF3 is studied experimentally as a function of the magnitude and direction of a constant magnetic field H at frequencies of 640–670 MHz, corresponding to the frequencies of nuclear spin waves. Two experimental situations are examined:
in the first, the vector H lies in the easy magnetization plane (001), and in the second, H forms an angle with (001). For longitudinal ultrasound waves propagating along the hard magnetization axis [001], it is found
that the damping depends resonantly on the magnitude of the field H. In the first case a single damping maximum is observed, and in the second, two damping peaks that are well resolved with
respect to the field. The angular dependence of the resonance damping signals on the direction of the constant magnetic field
is found to have a 90° periodicity in all cases. The observed effects are explained by resonant ultrasonic excitation of nuclear
spin waves. On the basis of an analysis of the magnetoacoustic interaction energy, it is shown that in the first case, nonzero
oscillations of the antiferromagnetism vector L occur only in the basal plane, while in the second, oscillations of L occur both in the basal and a vertical plane, which are associated, respectively, with two branches of the nuclear spin waves.
It is also shown that the 90° periodicity in the angular dependence of the damping signals is associated with a fourth order
[001] axis.
Zh. éksp. Teor. Fiz. 112, 1830–1840 (November 1997) 相似文献
16.
Effect of dispersion and damping in a communication channel on the secrecy of a quantum cryptosystem
S. N. Molotkov 《JETP Letters》1996,64(9):702-708
The effect of dispersion in the communication channel on the secrecy of a quantum cryptosystem based on the use of single-photon
states with different frequencies is investigated. The critical length of the communication channel such that confidentiality
of the key distribution can still be ensured is found.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 9, 652–657 (10 November 1996) 相似文献
17.
D. A. Ténné V. A. Gaisler A. K. Bakarov A. I. Toropov A. K. Gutakovskii A. P. Shebanin D. R. T. Zahn 《JETP Letters》1999,70(7):469-475
A Raman scattering method is used to investigate structures containing nanosize GaAs and AlAs clusters, which were grown by
molecular-beam epitaxy on InAs substrates by the mechanism of self-organized growth under mechanical stress. A large shift
of the phonon lines of GaAs and AlAs clusters with respect to the phonon frequencies in the bulk materials (36 and 24 cm−1 for GaAs LO and TO phonons and 55 and 28 cm−1 for AlAs LO and TO phonons, respectively) is observed in the spectra. This fact is explained by the presence of strong mechanical stresses in
the GaAs and AlAs clusters. A comparison of the experimental data with the computed strain dependences of the phonon frequencies
shows that the GaAs and AlAs clusters are pseudomorphic, i.e., they do not contain dislocations, which lead to relaxation
of the mechanical stresses. In the interval between the InAs TO and LO phonon frequencies, the Raman scattering spectra contain features associated with interfacial phonons. The position of these
features also attests to the formation of three-dimensional GaAs and AlAs islands and are described well by a continuum dielectric
model.
Pis’ma Zh. éksp. Teor. Fiz. 70, No. 7, 463–467 (10 October 1999) 相似文献
18.
L. K. Aminov I. N. Kurkin D. A. Lukoyanov K. P. Chernov 《Physics of the Solid State》1997,39(8):1184-1186
Results are reported for measurements of the spin-lattice relaxation times of E′1 centers in quartz glass, produced by neutron irradiation, with the measurements made at two frequencies 9.25 and 24.0 GHz
over a wide temperature interval 1.5–300 K. The experimental data are interpreted on the basis of interaction mechanisms of
the spins with two-level systems with excitation energies ∼6, ∼26, and ∼420 cm−1. A small modification of the existing theory allows us to explain a number of features of the observed temperature and frequency
dependence of the relaxation rate. The results are compared with the data available in the literature on spin-lattice relaxation
of irradiation centers in crystalline quartz and quartz glass.
Fiz. Tverd. Tela (St. Petersburg) 39, 1335–1337 (August 1997) 相似文献
19.
A. A. Voronkov B. P. Gorshunov V. S. Nozdrin E. S. Zhukova T. Matsuoka K. Tanaka S. Miyasaka S. Tajima M. Dressel 《JETP Letters》2012,94(9):708-713
The spectra of the conductivity and dielectric constant of La1.87Sr0.13CuO4 cuprate have been directly measured in the frequency range of 0.3 to 1.2 THz (10–40 cm−1) and the temperature range of 5 to 300 K in the E | c polarization (the electric field vector of radiation is perpendicular to the copper-oxygen planes). Excitation has been observed
in the superconducting phase, and its nature has been attributed to the transverse optical excitation of the condensate of
Cooper pairs, which appears because Josephson junctions between CuO planes are modulated due to in-plane magnetic and charge
stripes. Additional quasiparticle absorption of unknown origin has been detected at frequencies below ≈15 cm−1 at liquid helium temperatures. 相似文献
20.
The results of an experimental and theoretical investigation of strong turbulence produced by an external rf field in the
plasma of a beam-plasma discharge are presented. The modulation instability of a rf electric field, perpendicular to a constant
magnetic field, in the frequency range between the lower-hybrid and ionic Langmuir frequencies, has been investigated. It
is shown that the low-frequency fields can be used to control beam relaxation.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 9, 608–612 (10 November 1996) 相似文献