145 research outputs found

    Reply to the Comment of den Hartog and van Wees on "Conductance Fluctuations in Mesoscopic Normal-Metal/Superconductor Samples"

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    In their comment cond-mat/9710285 [Phys. Rev. Lett. 80, 5024 (1998)] den Hartog and van Wees (HW) raise objections against our analysis of the experimental data presented in cond-mat/9708162 [Phys. Rev. Lett. 79, 1547 (1997)]. According to HW, we did not account for the quantum phase incoherence introduced by the Niobium compounds of the investigated Nb/Au hybrid samples. Here we show that and why this criticism is not justified. Some difficulties associated with a precise determination of the coherence lengths are discussed. It is discussed why these uncertainties do not have a qualitative impact on the results reported in our paper.Comment: Reply to the comment cond-mat/9710285 by den Hartog and van Wees; 1 page REVTE

    Inducing an optical Feshbach resonance via stimulated Raman coupling

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    We demonstrate a novel method of inducing an optical Feshbach resonance based on a coherent free-bound stimulated Raman transition. In our experiment atoms in a Rb87 Bose-Einstein condensate are exposed to two phase-locked Raman laser beams which couple pairs of colliding atoms to a molecular ground state. By controlling the power and relative detuning of the two laser beams, we can change the atomic scattering length considerably. The dependence of scattering length on these parameters is studied experimentally and modelled theoretically.Comment: 8 pages, 8 figures, submitted to PR

    Dark state experiments with ultracold, deeply-bound triplet molecules

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    We examine dark quantum superposition states of weakly bound Rb2 Feshbach molecules and tightly bound triplet Rb2 molecules in the rovibrational ground state, created by subjecting a pure sample of Feshbach molecules in an optical lattice to a bichromatic Raman laser field. We analyze both experimentally and theoretically the creation and dynamics of these dark states. Coherent wavepacket oscillations of deeply bound molecules in lattice sites, as observed in one of our previous experiments, are suppressed due to laser-induced phase locking of molecular levels. This can be understood as the appearance of a novel multilevel dark state. In addition, the experimental methods developed help to determine important properties of our coupled atom / laser system.Comment: 20 pages, 9 figure

    Π’ΠΎΠ΄ΠΎΠΎΡ‚Π²Π΅Π΄Π΅Π½ΠΈΠ΅ Π½Π° ООО "ΠŸΠΈΠ²ΠΎΠ²Π°Ρ€Π½Ρ КоТСвниково" (Вомская ΠΎΠ±Π»Π°ΡΡ‚ΡŒ)

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    ΠžΠ±ΡŠΠ΅ΠΊΡ‚ΠΎΠΌ исслСдования являСтся очистныС сооруТСния. ЦСль Ρ€Π°Π±ΠΎΡ‚Ρ‹ – ΠΈΠ·ΡƒΡ‡Π΅Π½ΠΈΠ΅ эколого-экономичСского состояния очистных сооруТСний Π½Π° ООО Β«ΠŸΠΈΠ²ΠΎΠ²Π°Ρ€Π½Ρ КоТСвниково» Π³. Вомска. Π’ процСссС исслСдования ΠΏΡ€ΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈΡΡŒ ΡΠ»Π΅Π΄ΡƒΡŽΡ‰ΠΈΠ΅ Π²ΠΈΠ΄Ρ‹ Ρ€Π°Π±ΠΎΡ‚: ΠΎΡ‚Π±ΠΎΡ€ ΠΏΡ€ΠΎΠ± ΠΈ ΠΈΡ… транспортировка Π² Π³ΠΈΠ΄Ρ€ΠΎΠ³Π΅ΠΎΡ…ΠΈΠΌΠΈΡ‡Π΅ΡΠΊΡƒΡŽ ΠΈ ΠΌΠΈΠΊΡ€ΠΎΠ±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡ‡Π΅ΡΠΊΡƒΡŽ Π»Π°Π±ΠΎΡ€Π°Ρ‚ΠΎΡ€ΠΈΡŽ Π‘ΠΠ˜Π˜Π“Π“ΠΈΠœΠ‘ Π³. Вомска; Π°Π½Π°Π»ΠΈΠ· ΠΈ интСрпрСтация ΠΏΠΎΠ»ΡƒΡ‡Π΅Π½Π½Ρ‹Ρ… Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚ΠΎΠ² химичСского составов Π²ΠΎΠ΄; ΠΏΡ€ΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ эколого-экономичСской ΠΎΡ†Π΅Π½ΠΊΠΈ очистных сооруТСний; Π’ Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Π΅ исслСдования ΠΏΠΎΠ»ΡƒΡ‡Π΅Π½Ρ‹ Π½ΠΎΠ²Ρ‹Π΅ Π΄Π°Π½Π½Ρ‹Π΅ ΠΎ содСрТании вСщСств Π² ΠΏΠΎΠ΄Π·Π΅ΠΌΠ½Ρ‹Ρ… Π²ΠΎΠ΄Π°Ρ…, ΠΏΡ€ΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡ€ΠΎΠ²Π°Π½ΠΎ воздСйствиС ΠΏΡ€ΠΈΡ€ΠΎΠ΄Π½Ρ‹Ρ… ΠΈ Π°Π½Ρ‚Ρ€ΠΎΠΏΠΎΠ³Π΅Π½Π½Ρ‹Ρ… Ρ„Π°ΠΊΡ‚ΠΎΡ€ΠΎΠ² Π½Π° экологичСскоС состояниС ΠΏΠΎΠ΄Π·Π΅ΠΌΠ½Ρ‹Ρ… Π²ΠΎΠ΄ ΠΈ ΠΏΡ€ΠΈΠ»Π΅Π³Π°ΡŽΡ‰Π΅ΠΉ Ρ‚Π΅Ρ€Ρ€ΠΈΡ‚ΠΎΡ€ΠΈΠΈ, ΠΎΡ†Π΅Π½Π΅Π½ΠΎ качСство сточных Π²ΠΎΠ΄. ΠžΡΠ½ΠΎΠ²Π½Ρ‹Π΅ конструктивныС, тСхнологичСскиС ΠΈ Ρ‚Π΅Ρ…Π½ΠΈΠΊΠΎ-эксплуатационныС характСристики: комплСксноС использованиС очистных сооруТСний ΠΈ станции Π²ΠΎΠ΄ΠΎΠΏΠΎΠ΄Π³ΠΎΡ‚ΠΎΠ²ΠΊΠΈ. Π‘Ρ‚Π΅ΠΏΠ΅Π½ΡŒ внСдрСния: Π½Π°ΡƒΡ‡Π½ΠΎ-ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Ρ‚Π΅Π»ΡŒΡΠΊΠΈΠ΅ Ρ€Π°Π±ΠΎΡ‚Ρ‹.The CWA (Clean Water Act) established a control program for ensuring that communities have clean water by regulating the release of contaminants into our country’s waterways

    Long Distance Transport of Ultracold Atoms using a 1D optical lattice

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    We study the horizontal transport of ultracold atoms over macroscopic distances of up to 20 cm with a moving 1D optical lattice. By using an optical Bessel beam to form the optical lattice, we can achieve nearly homogeneous trapping conditions over the full transport length, which is crucial in order to hold the atoms against gravity for such a wide range. Fast transport velocities of up to 6 m/s (corresponding to about 1100 photon recoils) and accelerations of up to 2600 m/s2 are reached. Even at high velocities the momentum of the atoms is precisely defined with an uncertainty of less than one photon recoil. This allows for construction of an atom catapult with high kinetic energy resolution, which might have applications in novel collision experiments.Comment: 15 pages, 8 figure

    Conductance fluctuations in mesoscopic normal-metal/superconductor samples

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    We study the magnetoconductance fluctuations of mesoscopic normal-metal/superconductor (NS) samples consisting of a gold-wire in contact with a niobium film. The magnetic field strength is varied over a wide range, including values that are larger than the upper critical field B_c2 of niobium. In agreement with recent theoretical predictions we find that in the NS sample the rms of the conductance fluctuations (CF) is by a factor of 2.8 +/- 0.4 larger than in the high field regime where the entire system is driven normal conducting. Further characteristics of the CF are discussed.Comment: 4 pages, REVTEX, 3 eps-figures included. To be published in Phys. Rev. Lett.. Changes: one misplaced figure correcte

    Interferon beta-1a sc at 25 years: a mainstay in the treatment of multiple sclerosis over the period of one generation.

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    INTRODUCTION Interferon beta (IFN beta) preparations are an established group of drugs used for immunomodulation in patients with multiple sclerosis (MS). Subcutaneously (sc) applied interferon beta-1a (IFN beta-1a sc) has been in continuous clinical use for 25 years as a disease-modifying treatment. AREAS COVERED Based on data published since 2018, we discuss recent insights from analyses of the pivotal trial PRISMS and its long-term extension as well as from newer randomized studies with IFN beta-1a sc as the reference treatment, the use of IFN beta-1a sc across the patient life span and as a bridging therapy, recent data regarding the mechanisms of action, and potential benefits of IFN beta-1a sc regarding vaccine responses. EXPERT OPINION IFN beta-1a sc paved the way to effective immunomodulatory treatment of MS, enabled meaningful insights into the disease process, and remains a valid therapeutic option in selected vulnerable MS patient groups

    Fractal Conductance Fluctuations in Gold--Nanowires

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    A detailed analysis of magneto-conductance fluctuations of quasiballistic gold-nanowires of various lengths is presented. We find that the variance = = when analyzed for Ξ”B\Delta B much smaller than the correlation field BcB_c varies according to <(Ξ”G)2>βˆΞ”BΞ³<(\Delta G)^2>\propto \Delta B^{\gamma} with Ξ³<2\gamma < 2 indicating that the graph of GG vs. BB is fractal. We attribute this behavior to the existence of long-lived states arising from chaotic trajectories trapped close to regular classical orbits. We find that Ξ³\gamma decreases with increasing length of the wires.Comment: 5 pages, Revtex with epsf, 4 Postscript figures, final version accepted as Phys. Rev. Let
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