145 research outputs found
Reply to the Comment of den Hartog and van Wees on "Conductance Fluctuations in Mesoscopic Normal-Metal/Superconductor Samples"
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
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
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
ΠΠΎΠ΄ΠΎΠΎΡΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ Π½Π° ΠΠΠ "ΠΠΈΠ²ΠΎΠ²Π°ΡΠ½Ρ ΠΠΎΠΆΠ΅Π²Π½ΠΈΠΊΠΎΠ²ΠΎ" (Π’ΠΎΠΌΡΠΊΠ°Ρ ΠΎΠ±Π»Π°ΡΡΡ)
ΠΠ±ΡΠ΅ΠΊΡΠΎΠΌ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΎΡΠΈΡΡΠ½ΡΠ΅ ΡΠΎΠΎΡΡΠΆΠ΅Π½ΠΈΡ. Π¦Π΅Π»Ρ ΡΠ°Π±ΠΎΡΡ β ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅ ΡΠΊΠΎΠ»ΠΎΠ³ΠΎ-ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ ΠΎΡΠΈΡΡΠ½ΡΡ
ΡΠΎΠΎΡΡΠΆΠ΅Π½ΠΈΠΉ Π½Π° ΠΠΠ Β«ΠΠΈΠ²ΠΎΠ²Π°ΡΠ½Ρ ΠΠΎΠΆΠ΅Π²Π½ΠΈΠΊΠΎΠ²ΠΎΒ» Π³. Π’ΠΎΠΌΡΠΊΠ°. Π ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈΡΡ ΡΠ»Π΅Π΄ΡΡΡΠΈΠ΅ Π²ΠΈΠ΄Ρ ΡΠ°Π±ΠΎΡ: ΠΎΡΠ±ΠΎΡ ΠΏΡΠΎΠ± ΠΈ ΠΈΡ
ΡΡΠ°Π½ΡΠΏΠΎΡΡΠΈΡΠΎΠ²ΠΊΠ° Π² Π³ΠΈΠ΄ΡΠΎΠ³Π΅ΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΡΡ ΠΈ ΠΌΠΈΠΊΡΠΎΠ±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΡΡ Π»Π°Π±ΠΎΡΠ°ΡΠΎΡΠΈΡ Π‘ΠΠΠΠΠΠΈΠΠ‘ Π³. Π’ΠΎΠΌΡΠΊΠ°; Π°Π½Π°Π»ΠΈΠ· ΠΈ ΠΈΠ½ΡΠ΅ΡΠΏΡΠ΅ΡΠ°ΡΠΈΡ ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΎΠ² Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠ°Π²ΠΎΠ² Π²ΠΎΠ΄; ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ ΡΠΊΠΎΠ»ΠΎΠ³ΠΎ-ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΎΡΠ΅Π½ΠΊΠΈ ΠΎΡΠΈΡΡΠ½ΡΡ
ΡΠΎΠΎΡΡΠΆΠ΅Π½ΠΈΠΉ; Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΠΎΠ»ΡΡΠ΅Π½Ρ Π½ΠΎΠ²ΡΠ΅ Π΄Π°Π½Π½ΡΠ΅ ΠΎ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠΈ Π²Π΅ΡΠ΅ΡΡΠ² Π² ΠΏΠΎΠ΄Π·Π΅ΠΌΠ½ΡΡ
Π²ΠΎΠ΄Π°Ρ
, ΠΏΡΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½ΠΎ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ ΠΏΡΠΈΡΠΎΠ΄Π½ΡΡ
ΠΈ Π°Π½ΡΡΠΎΠΏΠΎΠ³Π΅Π½Π½ΡΡ
ΡΠ°ΠΊΡΠΎΡΠΎΠ² Π½Π° ΡΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ ΠΏΠΎΠ΄Π·Π΅ΠΌΠ½ΡΡ
Π²ΠΎΠ΄ ΠΈ ΠΏΡΠΈΠ»Π΅Π³Π°ΡΡΠ΅ΠΉ ΡΠ΅ΡΡΠΈΡΠΎΡΠΈΠΈ, ΠΎΡΠ΅Π½Π΅Π½ΠΎ ΠΊΠ°ΡΠ΅ΡΡΠ²ΠΎ ΡΡΠΎΡΠ½ΡΡ
Π²ΠΎΠ΄. ΠΡΠ½ΠΎΠ²Π½ΡΠ΅ ΠΊΠΎΠ½ΡΡΡΡΠΊΡΠΈΠ²Π½ΡΠ΅, ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈ ΡΠ΅Ρ
Π½ΠΈΠΊΠΎ-ΡΠΊΡΠΏΠ»ΡΠ°ΡΠ°ΡΠΈΠΎΠ½Π½ΡΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ: ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ½ΠΎΠ΅ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΎΡΠΈΡΡΠ½ΡΡ
ΡΠΎΠΎΡΡΠΆΠ΅Π½ΠΈΠΉ ΠΈ ΡΡΠ°Π½ΡΠΈΠΈ Π²ΠΎΠ΄ΠΎΠΏΠΎΠ΄Π³ΠΎΡΠΎΠ²ΠΊΠΈ. Π‘ΡΠ΅ΠΏΠ΅Π½Ρ Π²Π½Π΅Π΄ΡΠ΅Π½ΠΈΡ: Π½Π°ΡΡΠ½ΠΎ-ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°ΡΠ΅Π»ΡΡΠΊΠΈΠ΅ ΡΠ°Π±ΠΎΡΡ.The CWA (Clean Water Act) established a control program for ensuring that communities have clean water by regulating the release of contaminants into our countryβs waterways
Long Distance Transport of Ultracold Atoms using a 1D optical lattice
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
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.
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 25βyears 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
A detailed analysis of magneto-conductance fluctuations of quasiballistic
gold-nanowires of various lengths is presented. We find that the variance
when analyzed for much
smaller than the correlation field varies according to with indicating that the graph of
vs. 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 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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