107 research outputs found
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
Sur la possibilitĂŠ de dĂŠtermination du pouvoir ionisant d'une particule dans une chambre Ă ĂŠtincelles Ă petit intervalle
Full spin switch effect for the superconducting current in a superconductor/ferromagnet thin film heterostructure
Superconductor/ferromagnet (S/F) proximity effect theory predicts that the
superconducting critical temperature of the F1/F2/S or F1/S/F2 trilayers for
the parallel orientation of the F1 and F2 magnetizations is smaller than for
the antiparallel one. This suggests a possibility of a controlled switching
between the superconducting and normal states in the S layer. Here, using the
spin switch design F1/F2/S theoretically proposed by Oh et al. [Appl. Phys.
Lett. 71, 2376 (1997)], that comprises a ferromagnetic bilayer separated by a
non-magnetic metallic spacer layer as a ferromagnetic component, and an
ordinary superconductor as the second interface component, we have successfully
realized a full spin switch effect for the superconducting current.Comment: 5 pages, 4 figure
Evidence for Triplet Superconductivity in a Superconductor-Ferromagnet Spin Valve
We have studied the dependence of the superconducting (SC) transition
temperature on the mutual orientation of magnetizations of Fe1 and Fe2 layers
in the spin valve system CoO_x/Fe1/Cu/Fe2/Pb. We find that this dependence is
nonmonotonic when passing from the parallel to the antiparallel case and
reveals a distinct minimum near the orthogonal configuration. The analysis of
the data in the framework of the SC triplet spin valve theory gives direct
evidence for the long-range triplet superconductivity arising due to
noncollinearity of the two magnetizations.Comment: 5 pages (including 4 EPS figures). Version 2: final version as
published in PR
Noise-induced topological transformations of vortex solitons in optical fibers filled with a cold atomic gas
We consider the influence of optical and temperature-dependent atomic
fluctuations on the formation and propagation of optical vortex solitons in
dense media realized as hollow-core optical fibers filled with a cold atomic
gas in presence of optical pumping. We show different perturbation-induced
scenaria of complete destruction and smooth transformations of the topological
characteristics of localized optical structures in hollow-core fiber. The
maximum levels of optical and atomic fluctuations at which the soliton regime
can be maintained has been determined. The estimates for these levels show an
opportunity to observe the optical vortex solitions in the core-filling gas of
the fiber for temperatures smaller than the critical temperature for
Bose-Einstein condensate.Comment: 12 pages, 10 EPS figures, submitted to Physical Review
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<TcAP) spin valve effect for dFe2>=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
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