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31.
Quantum phase control of entanglement 总被引:2,自引:0,他引:2
A method of phase control of entanglement in two-qubit systems is proposed. We show that by changing a relative phase of the pulses that drive the transitions in a two-qubit system with closed-loop couplings, one can control entanglement at will. The method relies on adiabatic dynamics via time-delayed pulse sequences and can be implemented with both resonant and nonresonant transitions. 相似文献
32.
V. K. Malinovsky V. N. Novikov N. V. Surovtsev A. P. Shebanin 《Physics of the Solid State》2000,42(1):65-71
The vitreous SiO2 samples irradiated with fast neutrons at a dose of 5×1017?2.2×1020 per cm2 are investigated by the Raman scattering technique. It is demonstrated that the maximum of the low-frequency Raman spectrum (boson peak) shifts with an increase in the irradiation dose, and the medium-range order size decreases from 25 Å for the initial glass to 19 Å for the sample subjected to irradiation at a maximum dose. It is revealed that the fast relaxation intensity obtained from analysis of the low-frequency Raman spectra linearly correlates with the specific volume of the studied samples. 相似文献
33.
V. K. Malinovsky A. M. Pugachev N. V. Surovtsev 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(9):1231-1234
The Raman spectra of SBN crystals were recorded over wide spectral and temperature ranges. It is shown that a central peak representative of relaxation processes is observable in different spectral configurations of Raman measurements and cannot be described in the single relaxation time approximation. In the vicinity of the temperature corresponding to the onset of nucleation of polar regions (the Burns temperature), no specific features in the behavior of the central peak were observed. 相似文献
34.
We demonstrate the strong dependence of the entanglement dynamics of two distinguishable qubits in a trap on the relative phase of the pulses used for excitation. We show that the population and entanglement exhibits collapses and full revivals when the initial distribution of phonons is a coherent state. 相似文献
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36.
In a previous paper [Phys. Rev. A 72 (2005) 033415], it was shown that sub-Doppler cooling occurs in a standing-wave Raman scheme (SWRS) that can lead to reduced period optical lattices. These calculations are extended to allow for non-zero detuning of the Raman transitions. New physical phenomena are encountered, including cooling to non-zero velocities, combinations of Sisyphus and “corkscrew” polarization cooling, and somewhat unusual origins of the friction force. The calculations are carried out in a semi-classical approximation and a dressed state picture is introduced to aid in the interpretation of the results. 相似文献
37.
JETP Letters - The dynamics of intramolecular vibrational-energy redistribution from an initially excited mode ν1 (the acetylene-type H-C bond) to the other modes of the H-C≡C-Si(CH3)3... 相似文献
38.
Gonzalez-Vazquez J Sola IR Santamaria J Malinovsky VS 《The journal of physical chemistry. A》2007,111(14):2670-2678
By dynamic Stark shift using strong nonresonant pulses, we show that it is in principle possible to prepare arbitrary superposition states of mixed multiplicity. By a proper choice of parameters, the transfer of population is shown to follow the Rabi formula, where the initial and target states are now vibrational states of two light-induced molecular potentials of different multiplicity. Starting from nonstationary wave packets, the spin transfer can proceed via parallel transfer using a single pulse or by sequential transfer using a pulse sequence. A simple model is proposed to analyze the properties of both schemes and the feasibility of their experimental implementation for spin-orbit transitions in Rb2. 相似文献
39.
V.P. Solntsev A.V. Davydov V.K. Malinovsky N.V. Surovtsev 《Journal of Crystal Growth》2010,312(20):2962-2966
Melting and crystallization scenarios of barium tetraborate BaB4O7 (BaO·2B2O3) are studied in situ by Raman spectroscopy. It is shown that the scenario depends on the temperature–time history of melt. Crystallization conditions of the beta modification of barium tetraborate (β-BaB4O7) from a stoichiometric glass structure BaO·2B2O3 were investigated. 相似文献
40.
E. Pincik H. Kobayashi W.B. Kim L. Malinovsky K. Imamura M. Takahashi M. Kucera 《Applied Surface Science》2010,256(19):5757-5764
The properties of ultra-thin oxide/Si and very-thin oxide/Si structures prepared by wet chemical oxidation in nitric acid aqueous solutions (NAOS) and passivated in HCN aqueous solutions were investigated by electrical, optical and structural methods. n- and p-doped (1 0 0) crystalline Si substrates were used. There were identified more types of interface defect states in dependence on both post-oxidation treatment and passivation procedure. On samples prepared on n-type Si, continuous spectrum of defect states of 0.05-0.2 eV range and discrete defect traps, ∼ECB − 0.26 eV and ∼ECB − 0.39 eV, were found. All mentioned defects are related with various types of Si dangling bonds and/or with SiOx precipitates. Post-metallization annealing of investigated MOS structures reduced the interface defect density and suppressed the leakage currents. It did not change spectral profile of interface defect states in the Si band gap. In addition, there are presented following two optical phenomena: relation between amplitude of photoluminescence signal of NAOS samples and parameters of chemical oxidation process and quantum confinement effect observed on samples containing Si grains of size less as ∼2 nm. 相似文献