15,079 research outputs found
Yang-Yang thermodynamics on an atom chip
We investigate the behavior of a weakly interacting nearly one-dimensional
(1D) trapped Bose gas at finite temperature. We perform in situ measurements of
spatial density profiles and show that they are very well described by a model
based on exact solutions obtained using the Yang-Yang thermodynamic formalism,
in a regime where other, approximate theoretical approaches fail. We use
Bose-gas focusing [Shvarchuck etal., Phys. Rev. Lett. 89, 270404 (2002)] to
probe the axial momentum distribution of the gas, and find good agreement with
the in situ results.Comment: extended introduction and conclusions, and minor changes throughout;
accepted for publication in Phys. Rev. Let
Invariant measures for monotone SPDE's with multiplicative noise term
We study diffusion processes corresponding to infinite dimensional semilinear
stochastic differential equations with local Lipschitz drift term and an
arbitrary Lipschitz diffusion coefficient. We prove tightness and the Feller
property of the solution to show existence of an invariant measure. As an
application we discuss stochastic reaction diffusion equations.Comment: 10 page
Box traps on an atom chip for one-dimensional quantum gases
We present the implementation of tailored trapping potentials for ultracold
gases on an atom chip. We realize highly elongated traps with box-like
confinement along the long, axial direction combined with conventional harmonic
confinement along the two radial directions. The design, fabrication and
characterization of the atom chip and the box traps is described. We load
ultracold (K) clouds of Rb in a box trap, and demonstrate
Bose-gas focusing as a means to characterize these atomic clouds in arbitrarily
shaped potentials. Our results show that box-like axial potentials on atom
chips are very promising for studies of one-dimensional quantum gases.Comment: 9 pages 4 figure
Three-dimensional character of atom-chip-based rf-dressed potentials
We experimentally investigate the properties of radio-frequency-dressed
potentials for Bose-Einstein condensates on atom chips. The three-dimensional
potential forms a connected pair of parallel waveguides. We show that
rf-dressed potentials are robust against the effect of small magnetic-field
variations on the trap potential. Long-lived dipole oscillations of condensates
induced in the rf-dressed potentials can be tuned to a remarkably low damping
rate. We study a beam-splitter for Bose-Einstein condensates and show that a
propagating condensate can be dynamically split in two vertically separated
parts and guided along two paths. The effect of gravity on the potential can be
tuned and compensated for using a rf-field gradient.Comment: 9 pages, 7 figure
Yang-Yang thermodynamics on an atom chip
We investigate the behavior of a weakly interacting nearly one-dimensional
(1D) trapped Bose gas at finite temperature. We perform in situ measurements of
spatial density profiles and show that they are very well described by a model
based on exact solutions obtained using the Yang-Yang thermodynamic formalism,
in a regime where other, approximate theoretical approaches fail. We use
Bose-gas focusing [Shvarchuck etal., Phys. Rev. Lett. 89, 270404 (2002)] to
probe the axial momentum distribution of the gas, and find good agreement with
the in situ results.Comment: extended introduction and conclusions, and minor changes throughout;
accepted for publication in Phys. Rev. Let
Конституційно-правова природа Ради Міністрів Автономної Республіки Крим: дискусійні питання теорії та практики
У статті розкриваються особливості конституційно-правової природи Ради міністрів Автономної Республіки Крим. Показане місце Ради міністрів Автономної Республіки Крим серед інших органів публічної влади. Ключові слова: Рада міністрів Автономної Республіки Крим, Автономна Республіка Крим, уряд, автономія.В статье раскрываются особенности конституционно-правовой природы Совета министров Автономной Республики Крым. Показано место Совета министров Автономной Республики Крым среди других органов публичной власти. Ключевые слова: Совет министров Автономной Республики Крым, Автономная Республика Крым, правительство, автономия.In the article the features of constitutional and legal status of the Rada of Ministry of the Autonomous Republic of Crimea are analyzed. The place of the Rada of Ministry of the Autonomous Republic of Crimea between others organs of public power is defined. Key words: the Rada of Ministry of the Autonomous Republic of Crimea, the Autonomous Republic of Crimea, government, autonomy
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