共查询到20条相似文献,搜索用时 15 毫秒
1.
J.H. Thywissen M. Olshanii G. Zabow M. Drndić K.S. Johnson R.M. Westervelt M. Prentiss 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,7(3):361-367
We describe how tightly confining magnetic waveguides for atoms can be created with microfabricated or nanofabricated wires.
Rubidium atoms guided in the devices we have fabricated would have a transverse mode energy spacing of K. We discuss the creation of a single-mode waveguide for atom interferometry whose depth is comparable to magneto-optical
trap (MOT) temperatures. We also discuss the application of microfabricated waveguides to low-dimensional systems of quantum
degenerate gases, and show that confinement can be strong enough to observe fermionization in a strongly interacting bosonic
ensemble.
Received 1st December 1998 and Received in final form 23 February 1999 相似文献
2.
Reflection of cold atoms from an array of current-carrying wires 总被引:1,自引:0,他引:1
D.C. Lau A.I. Sidorov G.I. Opat R.J. McLean W.J. Rowlands P. Hannaford 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,5(2):193-199
We report the realization of a new type of magnetostatic mirror for slowly moving atoms which comprises a planar array of
parallel wires alternately carrying electric current in opposite directions. One of the features of this atomic mirror is
that the magnetic field may be readily varied, switched or modulated by altering the current in the wires. Reflection signals
close to 100% at a pulsed current of 3 A are demonstrated for a beam of free-falling laser-cooled cesium atoms at normal incidence.
The current dependence of the reflection signals exhibits structure which is associated with the sequential onset of reflection
of cesium 62
S
1/2
, F=4 atoms in the m=+4, +3, +2 and +1 magnetic states. Measurements of the spatial distribution of the reflected atoms indicate the reflection
is predominantly specular at currents of 3 A.
Received: 31 August 1998 / Accepted: 6 October 1998 相似文献
3.
T.J. Davis 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):111-118
The diffraction of laser-cooled atoms from a spatially-periodic potential is modelled using rigorous coupled-wave analysis.
This numerical technique, normally applied to light-diffraction, is adapted for use with atomic de Broglie waves incident
on a reflecting diffraction grating. The technique approximates the potential by a large number of constant layers and successively
solves the complex eigenvalue problem in each layer, propagating the solution up to the surface of the grating. The method
enables the diffraction efficiencies to be calculated for any periodic potential. The results from the numerical model are
compared with the thin phase-grating approximation formulae for evanescent light-wave diffraction gratings and idealised magnetic
diffraction gratings. The model is applied to the problem of diffracting Rb atoms from a grating made from an array of permanent
magnets.
Received 13 June 2000 and Received in final form 15 December 2000 相似文献
4.
É. Maréchal S. Guibal J.-L. Bossennec M.-P. Gorza R. Barbé J.-C. Keller O. Gorceix 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,2(3):195-198
The mechanical Stern-Gerlach effect is investigated in the case of a slow atomic cloud falling through an inhomogeneous magnetic
field featuring a strong longitudinal gradient. The resulting Zeeman sublevel state selection is demonstrated under various
experimental conditions. Longitudinal spatial separations are in agreement with numerical simulations that take into account
the gravitational acceleration and both the transverse and axial magnetic forces. Since separations greater than 20 cm are
obtained, potential applications in atom optics are outlined.
Received: 16 February 1998 / Received in final form: 1 April 1998 / Accepted: 6 April 1998 相似文献
5.
R.G. Dall M.D. Hoogerland D. Tierney K.G.H. Baldwin S.J. Buckman 《Applied physics. B, Lasers and optics》2002,74(1):11-18
We present a novel design for a single-mode, hollow optical fibre, which is suitable for use as a waveguide for atomic de
Broglie waves. The design, development and characterisation of such a fibre are discussed, as well as an optimised method
for coupling light into the fibre.
Received: 22 May 2001 / Revised version: 5 September 2001 / Published online: 29 November 2001 相似文献
6.
Improving the specularity of magnetic mirrors for atoms 总被引:1,自引:0,他引:1
G. Zabow M. Drndić J.H. Thywissen K.S. Johnson R.M. Westervelt M. Prentiss 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,7(3):351-359
An array of anti-parallel current-carrying wires creates an inhomogeneous magnetic field capable of reflecting neutral atoms.
We present analytical and numerical analyses of the magnetic field produced by such an array, and describe methods for reducing
the resulting rms angular deviation from specular reflection to less than 0.1 mrad. Careful choice of cross-sectional wire
profiles is shown to dramatically improve specularity of reflection close to the surface. Additionally, we find that the specularity
depends on whether the number of wires in the mirror is even or odd, and that there exists an optimal turning height above
the surface that maximizes the specularity of reflection from the mirror.
Received 16 November 1998 相似文献
7.
D. Cassettari A. Chenet R. Folman A. Haase B. Hessmo P. Krüger T. Maier S. Schneider T. Calarco J. Schmiedmayer 《Applied physics. B, Lasers and optics》2000,70(5):721-730
A large variety of trapping and guiding potentials can be designed by bringing cold atoms close to charged or current carrying
material objects. We describe the basic principles of constructing microscopic traps and guides and how to load atoms into
them. The simplicity and versatility of these methods will allow for miniaturization and integration of atom optical elements
into matter-wave quantum circuits on Atom Chips. These could form the basis for robust and widespread applications in atom optics, ranging from fundamental studies in mesoscopic
physics to possibly quantum information systems.
Received: 20 December 1999 / Revised version: 7 March 2000 / Published online: 5 April 2000 相似文献
8.
U.V. Poulsen K. Mølmer 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(2):151-157
We present theoretical calculations for the reflection of atoms from a magnetic surface with a sinusoidal magnetization. A
fully quantum mechanical treatment is possible because the problem may be reduced to an effective one-dimensional one. Results
of numerical wave-packet calculations are presented and compared with an analytical model in which the atoms separate into
different internal state components which follow classical paths in different potentials.
Received 21 October 1999 and Received in final form 18 January 2000 相似文献
9.
B. Viaris de Lesegno J.C. Karam M. Boustimi F. Perales C. Mainos J. Reinhardt J. Baudon V. Bocvarski D. Grancharova F. Pereira Dos Santos T. Durt H. Haberland J. Robert 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(1):25-34
A new Stern Gerlach interferometer operating with a nozzle beam of metastable argon atoms Ar* (3p5 4s, 3
P
2) is described. The selection of incoming (polarisation) and outgoing (analysis) Zeeman sublevels is achieved by use of laser
induced transitions at two wavelengths, 811.5 nm (closed J = 2 → J = 3 transition) and 801.5 nm (open J = 2 → J = 2 transition). Linear superpositions of Zeeman sublevels, just beyond the polariser and just before the analyser, are prepared
by means of two zones where Majorana transitions take place. In between, a controlled magnetic field configuration (the phase
object) is produced within a triple μ-metal shielding. Standard interference patterns are obtained by scanning the field and
detecting the atoms by secondary electron emission from a Faraday cup. When a static radial magnetic gradient is used, the
beam profile is modulated by interference. The transverse pattern, which can be translated at will by adding a homogeneous
field, is observed for the first time using a multi-channel electron multiplier followed by a phosphor screen and a CCD camera.
The results satisfactorily agree with all theoretical predictions.
Received 27 June 2002 / Received in final form 20 September 2002 Published online 4 February 2003
RID="a"
ID="a"e-mail: perales@lpl.univ-paris13.fr
RID="b"
ID="b"UMR 7538 du CNRS 相似文献
10.
T.J. Davis 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(3):289-297
The problem of atom diffraction from a reflecting magnetic diffraction grating is solved in the thin phase-grating approximation.
The general problem for scalar diffraction is modelled using a semi-classical method in which the grating potential is separated
into a reflecting term and a diffracting term. The trajectory of the atom in the reflecting potential is solved classically
and the atom wave function in the diffracting potential found by integrating the phase change along the classical trajectory.
The diffraction orders are obtained after Fourier transforming the result. This can be done independently of the grating potential
resulting in a general formula for the diffraction efficiencies. The general result is applied to the problem of atom diffraction
from a magnetic grating. Several approximations are required to reduce the problem to a form amenable to analytic solution.
The results are compared with an accurate numerical method.
Received 1st February 2001 and Received in final form 8 March 2001 相似文献
11.
S. Gleyzes A. El Amili R. A. Cornelussen P. Lalanne C. I. Westbrook A. Aspect J. Estève G. Moreau A. Martinez X. Lafosse L. Ferlazzo J. C. Harmand D. Mailly A. Ramdane 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(1):107-111
We study a Fabry-Perot cavity formed from a ridge waveguide on a AlGaAs substrate. We experimentally determined the propagation
losses in the waveguide at 780 nm, the wavelength of Rb atoms. We have also made a numerical and analytical estimate of the
losses induced by the presence of the gap which would allow the interaction of cold atoms with the cavity field. We found
that the intrinsic finesse of the gapped cavity can be on the order of F∼30, which, when one takes into account the losses
due to mirror transmission, corresponds to a cooperativity parameter for our system C∼1. 相似文献
12.
C. Klempt T. Henninger O. Topic J. Will St. Falke W. Ertmer J. Arlt 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,48(1):121-126
We report on the simultaneous transport of mixed quantum
degenerate gases of bosonic 87Rb and fermionic 40
K in a harmonic potential. The samples are transported over a
distance of
to the geometric center of a
Ioffe-Pritchard type magnetic trap. This transport mechanism was
implemented by modification of the QUIC trap and is free of losses
and heating. It significantly extends the capabilities of this trap
design. We demonstrate a launching mechanism for quantum degenerate
samples and show that highly homogeneous magnetic fields can be
created in the center of the QUIC trap. The transport mechanism may
also be cascaded to cover even larger distances for interferometric
experiments with quantum degenerate samples. 相似文献
13.
A lattice of magneto-optical and magnetic traps for cold atoms 总被引:1,自引:0,他引:1
A. Grabowski T. Pfau 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(3):347-354
We describe basic periodic trapping configurations for ultracold atoms above surfaces. The approach is based on a simple wire
grid and can be scaled to provide large arrays of periodically arranged magnetic or magneto-optical traps. The unit cells
of the trap lattices are based on crossed wire segments. By alternating the current directions in the wires of the grid it
can be distinguished between 3 basic lattice configurations. As a first demonstration, we used macroscopic wires in a 2 layer
configuration to realize the unit cells of the lattices. With this experimental setup, we observe two of the basic unit cells
and an array of 2×2 magneto optical traps.
Received 29 August 2002 / Received in final form 12 December 2002 Published online 18 February 2003 相似文献
14.
N. Liu W. Gao J. Yin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(2):137-145
A new scheme to magnetically guide cold, neutral atoms using a V-shaped current-carrying conductor is proposed. The spatial
distributions of the magnetic fields, potentials and forces generated by the V-shaped current-carrying conductor are calculated,
and the relationship between the magnetic field and the parameters of the V-shaped current-carrying conductor are analyzed
in detail. Our study shows that the V-shaped current-carrying conductor proposed here can be used to guide cold atoms in the
weak-field-seeking state, and to construct various atom-optical elements, such as atomic funnel, atomic beam-splitter and
atom interferometer and so on, and even to realize a single-mode atomic waveguiding under certain conditions.
Received 17 November 2000 and Received in final form 26 May 2001 相似文献
15.
Neerja A.N. Tripathi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,13(1):5-10
We present calculations of differential, integrated elastic, total, momentum transfer cross-sections and spin-polarization
parameters S, T and U for scattering of electrons from Eu and Bi atoms in the energy range 2.0 to 500.0 eV using semi-relativistic approach. The
target-projectile interaction is represented both by real and complex parameter-free optical potentials in the solution of
Dirac equation for the scattered electrons. The results for the differential cross-sections and spin-polarization parameters
have been compared with the available calculations and experimental results.
Received 17 February 2000 and Received in final form 15 June 2000 相似文献
16.
U. Drodofsky J. Stuhler T. Schulze M. Drewsen B. Brezger T. Pfau J. Mlynek 《Applied physics. B, Lasers and optics》1997,65(6):755-759
52 Cr, different patterns can be generated. Possible applications using the inherent properties of atom lithography, e.g. the
fabrication of photonic bandgap material, are discussed.
Received: 10 March 1997/Revised version: 12 May 1997 相似文献
17.
H. Ellmann J. Jersblad A. Kastberg 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,13(3):379-384
A detailed experimental study of the steady-state temperature in a 3D optical lattice for cesium has been performed for a
wide range of detunings. Specifically, we have investigated the situation with the cooling and trapping light detuned far
red of a ( J
g↦J
e = J
g + 1)-transition, where the blue detuned interaction with a ( J
g↦J
e = J
g)-transition can not be neglected. We find that the temperature scales with the optical potential due to the interaction with
just the ( J
g↦J
e = J
g + 1)-transition. This indicates that blue Sisyphus cooling has essentially no effect on the dynamics of the system, when
there exists a neighbouring red detuned transition.
Received 6 June 2000 and Received in final form 26 September 2000 相似文献
18.
Miniaturized magnetic guide for neutral atoms 总被引:1,自引:0,他引:1
J. Fortagh H. Ott A. Grossmann C. Zimmermann 《Applied physics. B, Lasers and optics》2000,70(5):701-708
We describe the principle and realization of a miniaturized magnetic guide for neutral atoms. The magnetic guide in our experiment
is formed by a micrometer-sized current-carrying wire which is attached to a second, thick wire. The conductors are electrically
insulated from each other. The combined magnetic field of both conductors provides an approximately linear trapping potential
which establishes a magnetic guide along the surface of the thin wire. The miniaturized waveguide is filled with rubidium
atoms from a magneto-optical trap (MOT) by first loading the atoms into a spherical magnetic quadrupole trap which is subsequently
transformed into the linear potential of the waveguide. As thermal source for Rb atoms we use an alkali metal dispenser which
is located close to the center of the MOT. This novel method is compatible with ultrahigh vacuum conditions and we achieved
lifetimes of the magnetically trapped atoms up to 100 s.
Received: 18 October 1999 / Published online: 24 March 2000 相似文献
19.
J. Denschlag D. Cassettari A. Chenet S. Schneider J. Schmiedmayer 《Applied physics. B, Lasers and optics》1999,69(4):291-301
A large variety of trapping and guiding potentials can be designed by bringing cold atoms close to charged or current-carrying
material objects. Using a current-carrying wire we demonstrate how to build guides and traps for neutral atoms and using a
charged wire we study a 1/r
2 singularity. The simplicity and versatility of the principles demonstrated in our experiments will allow for miniaturization
and integration of atom optical elements into matter-wave quantum circuits.
Received: 13 December 1998 / Revised version: 8 July 1999 / Published online: 8 September 1999 相似文献
20.
J. Grucker J. Baudon F. Perales G. Dutier V. Bocvarski J.-C. Karam G. Vassilev M. Ducloy 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(3):427-431
Surface-induced exo-energetic inelastic transitions among atomic Zeeman
states in a magnetic field (“van der Waals – Zeeman” transitions) are
useable as tuneable beam splitters. A transversally coherent atom beam
impinging a pair of opposite surfaces (e.g. 2 edges of a slit or of an ensemble
of periodic slits) gives rise to two coherently diffracted wave packets.
Within the wave packet overlap, non-localised interference fringes of the
Young-slit type are predicted. From the diffraction pattern observed in the
Fraunhofer regime (Schlieren image), detailed information about the
transition amplitude on a scale of a few nanometers should be derived. 相似文献