53,722 research outputs found
Thermal neutron image intensifier tube provides brightly visible radiographic pattern
Vacuum-type neutron image intensifier tube improves image detection in thermal neutron radiographic inspection. This system converts images to an electron image, and with electron acceleration and demagnification between the input target and output screen, produces a bright image viewed through a closed circuit television system
Analytical mode normalization and resonant state expansion for optical fibers - an efficient tool to model transverse disorder
We adapt the resonant state expansion to optical fibers such as capillary and
photonic crystal fibers. As a key requirement of the resonant state expansion
and any related perturbative approach, we derive the correct analytical
normalization for all modes of these fiber structures, including leaky modes
that radiate energy perpendicular to the direction of propagation and have
fields that grow with distance from the fiber core. Based on the normalized
fiber modes, an eigenvalue equation is derived that allows for calculating the
influence of small and large perturbations such as structural disorder on the
guiding properties. This is demonstrated for two test systems: a capillary
fiber and an endlessly single mode fiber.Comment: 10 pages, 4 figure
Quasideuteron configurations in 46V and 58Cu
The data on low spin states in the odd-odd nuclei 46V and 58Cu investigated
with the 46Ti(p,ngamma)46V, 32S(16O,pn)46V and 58Ni(p,ngamma)58Cu reactions at
the FN-TANDEM accelerator in Cologne are reported. The states containing large
quasideuteron components are identified from the strong isovector M1
transitions, from shell model calculations and from experimental data for
low-lying states.Comment: 6 pages, 3 figures, proceedings of the "Nuclear Structure 2000"
conference, East Lansing, Michigan, USA, August 15-19, 2000; to appear in
Nucl. Phys.
Voltage-Controlled Spin Selection in a Magnetic Resonant Tunnelling Diode
We have fabricated all II-VI semiconductor resonant tunneling diodes based on
the (Zn,Mn,Be)Se material system, containing dilute magnetic material in the
quantum well, and studied their current-voltage characteristics. When subjected
to an external magnetic field the resulting spin splitting of the levels in the
quantum well leads to a splitting of the transmission resonance into two
separate peaks. This is interpreted as evidence of tunneling transport through
spin polarized levels, and could be the first step towards a voltage controlled
spin filter.Comment: To be published in Phys. Rev. Let
The fate of 1D spin-charge separation away from Fermi points
We consider the dynamic response functions of interacting one dimensional
spin-1/2 fermions at arbitrary momenta. We build a non-perturbative
zero-temperature theory of the threshold singularities using mobile impurity
Hamiltonians. The interaction induced low-energy spin-charge separation and
power-law threshold singularities survive away from Fermi points. We express
the threshold exponents in terms of the spinon spectrum.Comment: 5 pages, 1 figur
The key aspects of innovation-oriented regional industrial and economic policy
Integration processes taking place in the economy, the new requirements to enhance the effectiveness of production during international competition as well as the need to ensure the social conditions lead to the development and implementation of innovation-oriented regional industrial and economic policy, which in its turn, requires adopting substantial organizational and economic recommendations
Manifestation of New Interference Effects in Superconductor/Ferromagnet Spin Valve
Superconductor/ferromagnet (S/F) spin valve effect theories based on the S/F
proximity phenomenon assume that the superconducting transition temperature Tc
of F1/F2/S or F1/S/F2 trilayers for parallel magnetizations of the F1- and
F2-layers (TcP) are smaller than for the antiparallel orientations (TcAP).
Here, we report for CoOx/Fe1/Cu/Fe2/In multilayered systems with varying
Fe2-layer thickness the sign-changing oscillating behavior of the spin valve
effect \Delta Tc=TcAP-TcP. Our measurements revealed the full direct spin valve
effect with TcAP>TcP for Fe2-layer thickness dFe2<1 nm and the full inverse
(TcAP=1 nm. Interference of Cooper pair wave
functions reflected from both surfaces of the Fe2-layer appear as the most
probable reason for the observed behavior of \Delta Tc.Comment: Accepted for publication in PR
Chiral Three-Nucleon Interactions in Light Nuclei, Neutron- Scattering, and Neutron Matter
We present quantum Monte Carlo calculations of light nuclei, neutron-
scattering, and neutron matter using local two- and three-nucleon ()
interactions derived from chiral effective field theory up to
next-to-next-to-leading order (NLO). The two undetermined low-energy
couplings are fit to the He binding energy and, for the first time, to the
spin-orbit splitting in the neutron- -wave phase shifts.
Furthermore, we investigate different choices of local -operator structures
and find that chiral interactions at NLO are able to simultaneously
reproduce the properties of systems and of neutron matter, in
contrast to commonly used phenomenological interactions.Comment: 5 pages, 3 figures, 1 table - updated version: small wording changes,
one reference chang
Quantum state conversion by cross-Kerr interaction
A generalized Mach-Zehnder-type interferometer equipped with cross-Kerr
elements is proposed to convert N-photon truncated single-mode quantum states
into (N+1)-mode single-photon states, which are suitable for further state
manipulation by means of beam splitter arrays and ON/OFF-detections, and vice
versa. Applications to the realization of unitary and non-unitary
transformations, quantum state reconstruction, and quantum telemanipulation are
studied.Comment: 22 pages, 4 figures, using a4.st
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