256 research outputs found
Quantum temporal imaging: application of a time lens to quantum optics
We consider application of a temporal imaging system, based on the
sum-frequency generation, to a nonclassical, in particular, squeezed optical
temporal waveform. We analyze the restrictions on the pump and the phase
matching condition in the summing crystal, necessary for preserving the quantum
features of the initial waveform. We show that modification of the notion of
the field of view in the quantum case is necessary, and that the quantum field
of view is much narrower than the classical one for the same temporal imaging
system. These results are important for temporal stretching and compressing of
squeezed fields, used in quantum-enhanced metrology and quantum communications.Comment: 9 pages, 3 figure
Study of the evolution of the Cu/Nb interphase boundary by the molecular dynamics method
The evolution of atomic structure of the interphase boundary for composites from immiscible Cu/Nb elements is studied by the molecular dynamics method. It is established that the planar interphase boundary is stable at temperatures up to 1200 K. Atomic dissolution of elements is not revealed in the entire examined temperature interval, and the components are mixed on the interphase boundary of finite curvature in the form of clusters and nanolamellas; moreover, the amorphous state is not formed in the process of migration of the interphase boundaryyesBelgorod State Universit
Self-diffusion parameters of grain boundaries and triple junctions in nanocrystalline materials
Suggested methods describe the process of self-diffusion along grain boundaries and triple junctions in polycrystals without using geometric models of the grain boundaries structure. The calculation method introduced diffusion characteristics along grain boundaries derived from the results of molecular dynamic simulations of nanocrystalline materialsyesBelgorod State Universit
Characteristics of the electric field accompanying a longitudinal acoustic wave in a metal. Anomaly in the superconducting phase
The temperature dependence of the amplitude and phase of the electric
potential arising at a plane boundary of a conductor when a longitudinal
acoustic wave is incident normally on it is investigated theoretically and
experimentally. The surface potential is formed by two contributions, one of
which is spatially periodic inside the sample, with the period of the acoustic
field; the second is aperiodic and arises as a result of an additional
nonuniformity of the electron distribution in a surface layer of the metal. In
the nonlocal region the second contribution is dominant. The phases of these
contributions are shifted by approximately \pi /2. For metals in the normal
state the experiment is in qualitative agreement with the theory. The
superconducting transition is accompanied by catastrophically rapid vanishing
of the electric potential, in sharp contrast to the theoretical estimates,
which predict behavior similar to the BCS dependence of the attenuation
coefficient for a longitudinal sound.Comment: 9 pages, 6 figure
Systematic analysis of SNR in bipartite Ghost Imaging with classical and quantum light
We present a complete and exhaustive theory of signal-to-noise-ratio in
bipartite ghost imaging with classical (thermal) and quantum (twin beams)
light. The theory is compared with experiment for both twin beams and thermal
light in a certain regime of interest
Entangled-State Lithography: Tailoring any Pattern with a Single State
We demonstrate a systematic approach to Heisenberg-limited lithographic image
formation using four-mode reciprocal binominal states. By controlling the
exposure pattern with a simple bank of birefringent plates, any pixel pattern
on a grid, occupying a square with the side half a
wavelength long, can be generated from a -photon state.Comment: 4 pages, 4 figure
Molecular-dynamics simulation of the α-Ti plastic deformation under conditions of high-energy effects
Modeling of high-speed deformation of α-Ti at a pressure of 20 GPa and a temperature of 700 K simulating the conditions of high-energy effects is carried out. The mechanisms of plastic deformation, including sliding along prismatic planes and the α-ω transition, are established. A feature of the deformation process of titanium in the considered conditions, which leads to the formation of disperse inclusions of the α-phase in the ω-phase matrix, is reveale
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