共查询到20条相似文献,搜索用时 31 毫秒
1.
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
2.
Yu.L. Sokolov V.P. Yakovlev V.G. Pal'chikov Yu.A. Pchelin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(1):27-36
The properties of two-dimensional magnetic traps for laser-cooled atoms are analysed using complex functions. The two components
of the magnetic field from a series of parallel, infinitely long, current-carrying wires are represented by a single complex
number. The regions of the field where paramagnetic atoms can be trapped occur where the magnetic field is zero. The locations
of the zeroes of the field are obtained as the solution to a polynomial and the multiplicity m of the solution determines both the 2(m + 1)-pole nature of the trap and the field gradient through the centre. The zeroes of the field can be merged or split by
varying the locations of the currents, their strengths or by applying a uniform magnetic field. The theory is applied to magnetic
traps created from long thin wires or permanent magnets on a substrate. The properties of a number of magnetic trap configurations
used for atom guides are discussed.
Received 28 February 2001 and Received in final form 6 July 2001 相似文献
3.
We propose a controllable double-well magneto-optic trap (MOT) for neutral atoms that uses a circular current-carrying wire and a biased magnetic field. One can cause the proposed double-well trap to evolve continually into a single-well trap by reducing the current in the wire or increasing the bias field. We estimate that in a weak intensity approximation a cold atomic sample with a temperature of approximately 300 K and a number of approximately 10(6) atoms can be stored in each MOT. One can control the number of trapped atoms by changing the current in the wire. 相似文献
4.
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
5.
Arrays of microscopic magnetic traps for cold atoms and their applications in atom optics 总被引:2,自引:0,他引:2 下载免费PDF全文
A single microscopic magnetic trap for neutral atoms using planar current-carrying wires was proposed and studied theoretically by Weinstein et al.In this paper,we propose three structures of composite current-carrying wires to provide 1D,2D and 3D arrays of microscopic magnetic traps for cold alkali atoms.The spatial distributions of magnetic fields generated by these structures are calculated and the field gradient and curvature in each single microtrap are analysed.Our study shows that arrays of microscopic magnetic traps can be used to provide 1D,2D or 3D atomic magnetic lattices,and even to realize 1D,2D and 3D arrays of magneto-optical traps,and so on. 相似文献
6.
We experimentally demonstrate the trapping of ^85Rb atoms directly on a chip-size U-shaped magneto-optical trap (U-MOT). The trap includes a U-shaped wire on the chip, two bias magnetic field coils and laser beams. The capture volume of the U-MOT is theoretically calculated, and the trap is experimentally realized. With 2 A current applied to the U-shaped wire and 2-Gauss horizontal bias field, more than 2 × 10^6 atoms are trapped. In contrast with an ordinary mirror-MOT, this U-MOT captures atoms directly from the background, thus the trap size is greatly reduced. Based on this mini trap scheme, it is possible to realize a chip-size atom trap array for quantum information processing. 相似文献
7.
A novel magnetic trap for confining ultracold neutral atoms in a ring
is proposed. The magnetic trap is generated by a microfabricated
ferromagnetic structure integrated on an “atom chip”.
The structure is based on previously demonstrated fabrication
techniques and is capable of creating tightly confining reciprocal
traps with trap frequencies as large as 50 kHz. Also, the trap
exhibits significantly smaller magnetic field inhomogeneities
compared to other proposals for current-based reciprocal traps.
The suitability of this trap for atom interferometry and the
study of low dimensional ultracold systems is outlined. 相似文献
8.
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
9.
Guiding Neutral Atoms with Two Current-Carrying Wires and a Vertical Bias Field on the Atom Chip 总被引:1,自引:0,他引:1 下载免费PDF全文
We demonstrate the guiding of neutral atoms with two parallel microfabricated current-carrying wires on the atom chip and a vertical magnetic bias field. The atoms are guided along a magnetic field minimum parallel to the current-carrying wires and confined in the other two directions. We describe in detail how the precooled atoms are efficiently loaded into the two-wire guide. We present a detailed experimental study of the motional properties of the atoms in the guide and the relationship between the location of the guide and the vertical bias field. This two-wire guide with vertical bias field can be used to realize large area atom interferometer. 相似文献
10.
M. Drewsen Ph. Laurent A. Nadir G. Santarelli A. Clairon Y. Castin D. Grison C. Salomon 《Applied physics. B, Lasers and optics》1994,59(3):283-298
We present an investigation of sub-Doppler effects in a cesium magneto-optical trap. First, a simple one-dimensional theoretical model of the trap is developed for aJ
g = 1 J
e = 2 transition. This model predicts the size of the trapped atom cloud and temperature as a function of laser intensity and detuning. In the limit of small magnetic field gradients, the trap temperature is found to be equal to the molasses temperature and a minimum size for the trap is calculated. We then describe several experiments performed in a three-dimensional cesium trap to measure the trap parameters, spring constant, friction coefficient, temperature and density. Whilst the temperature of the trapped atoms is found to be equal to the molasses temperature, in agreement with theory, the trap spring constant is found to be two orders of magnitude smaller than the one-dimensional prediction, a value close to that predicted by Doppler models. The maximum density is found to be on the order of 1012 atoms/cm3 or one atom per optical wavelength on average. When the number of trapped atoms becomes large, the temperature begins to increase dramatically. This excess temperature depends in a very simple way on the atom number, laser intensity and detuning, suggesting that its origin lies in multiple photon scattering within the trap. 相似文献
11.
J. Reichel 《Applied physics. B, Lasers and optics》2002,74(6):469-487
The article gives an overview of the rapidly evolving field of magnetic microchip traps (also called ‘atom chips’) for neutral
atoms. Special attention is given to Bose–Einstein condensation in such traps, to the particular properties of microchip trap
potentials, and to practical considerations in their design. Scaling laws are developed, which lead to an estimate of the
ultimate confinement that chip traps can provide. Future applications such as integrated atom interferometers are discussed.
Received: 28 March 2002 / Published online: 14 May 2002 相似文献
12.
Ph.W. Courteille S.R. Muniz K. Magalhães R. Kaiser L.G. Marcassa V.S. Bagnato 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(2):173-180
Neutral atoms may be trapped via the interaction of their magnetic dipole moment with magnetic field gradients. One of the possible schemes is the cloverleaf
trap. It is often desirable to have at hand a fast and precise technique for measuring the magnetic field distribution. We
use for instantaneous imaging the equipotential lines of the magnetic field a diagnostic tool which is based on spatially
resolved observation of the fluorescence emitted by a hot beam of sodium atoms crossing a thin slice of resonant laser light
within the magnetic field region to be investigated. The inhomogeneous magnetic field spatially modulates the resonance condition
between the Zeeman-shifted hyperfine sublevels and the laser light and therefore the amount of scattered photons. We apply
this technique for mapping the field of our cloverleaf trap in three dimensions under various conditions.
Received 20 March 2001 and Received in final form 12 May 2001 相似文献
13.
A new scheme for trapping Cs atoms in a non dissipative trap has been developed. The trap involves both optical dipole forces
and magnetic forces. This device is suitable for Cs atoms in the lowest energy Zeeman sublevel, thus avoiding the two-body
inelastic collisions which prevented reaching Bose-Einstein condensation of Cs in purely magnetic traps. Furthermore, an additional
magnetic field can be applied, allowing a fine tuning of the two-body elastic collision cross-section. We report on the experimental
realization of such a trap and describe the characteristics of the trapped atomic sample. An analysis of the collisional regime
is performed using measurements of the damping of the oscillatory modes of the trapped atom cloud. 相似文献
14.
S. K. Tokunaga W. Skomorowski P. S. Żuchowski R. Moszynski J. M. Hutson E. A. Hinds M. R. Tarbutt 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,65(1-2):141-149
We consider how trapped molecules can be sympathetically cooled by ultracold atoms. As a prototypical system, we study LiH molecules co-trapped with ultracold Li atoms. We calculate the elastic and inelastic collision cross sections of 7LiH + 7Li with the molecules initially in the ground state and in the first rotationally excited state. We then use these cross sections to simulate sympathetic cooling in a static electric trap, an ac electric trap, and a microwave trap. In the static trap we find that inelastic losses are too great for cooling to be feasible for this system. The ac and microwave traps confine ground-state molecules, and so inelastic losses are suppressed. However, collisions in the ac trap can take molecules from stable trajectories to unstable ones and so sympathetic cooling is accompanied by trap loss. In the microwave trap there are no such losses and sympathetic cooling should be possible. 相似文献
15.
We trap neutral ground-state rubidium atoms in a macroscopic trap based on purely electric fields. For this, three electrostatic field configurations are alternated in a periodic manner. The rubidium is precooled in a magneto-optical trap, transferred into a magnetic trap, and then translated into the electric trap. The electric trap consists of six rod-shaped electrodes in cubic arrangement, giving ample optical access. Up to 10;{5} atoms have been trapped with an initial temperature of around 20 microkelvin in the three-phase electric trap. The observations are in good agreement with detailed numerical simulations. 相似文献
16.
V. Dikovsky V. Sokolovsky B. Zhang C. Henkel R. Folman 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,51(2):247-259
Superconductors are considered in view of applications to atom chip devices. The main features of magnetic traps based on
superconducting wires in the Meissner and mixed states are discussed. The former state may mainly be interesting for improved
atom optics, while in the latter, cold atoms may provide a probe of superconductor phenomena. The properties of a magnetic
side guide based on a single superconducting strip wire placed in an external magnetic field are calculated analytically and
numerically. In the mixed state of type II superconductors, inhomogeneous trapped magnetic flux, relaxation processes and
noise caused by vortex motion are posing specific challenges for atom trapping. 相似文献
17.
Small transverse magnetic quadrupole fields sharply degrade the confinement of non-neutral plasmas held in Malmberg-Penning traps. For example, a quadrupole magnetic field of only 0.02 G/cm doubles the diffusion rate in a trap with a 100 G axial magnetic field. Larger quadrupole fields noticeably change the shape of the plasma. The transport is greatest at an orbital resonance. These results cast doubt on plans to use magnetic quadrupole neutral atom traps to confine antihydrogen atoms created in double-well positron/antiproton Malmberg-Penning traps. 相似文献
18.
提出了一种新的采用载流导线的表面双磁光阱(MOT)方案(即双U型导线磁光阱方案)。通过改变中间U型导线中的电流大小,即可将一个双磁阱连续地合并为一个单磁阱,反之亦然。详细计算和分析了上述双U型载流导线磁光阱方案的磁场及其梯度的空间分布,研究发现当导线中的电流为600 A,z方向均匀偏置磁感应强度为-4.0×10-3 T时,双U型导线方案产生的两个磁阱中心的磁场梯度约为1.5×10-3~2.5×10-3 T/cm,结合通常制备磁光阱时所用的三维粘胶(Molasses)光束即可在基底表面附近形成一双磁光阱。理论分析表明在弱光近似下,每个磁光阱中所能俘获的85Rb原子数约为106 量级,相应的磁光阱温度约为270μK。由于双磁光阱可以独立制备,所以双U型导线方案特别适用于制备双样品磁光阱,并用于研究双原子样品的冷碰撞性质。 相似文献
19.
We put forward the idea of a surface-mounted microscopic electro-optical atom trap. The trap is formed on an evanescent-wave atom mirror by the strongly localized static electric field of two oppositely charged transparent electrodes placed close to each other. The electrodes are embedded in a refractive-index-matched thin dielectric layer on the surface of a glass prism. In our example, the phase-space density in the trap center reaches 0.1, when the trap is loaded with atoms from a gravito-optical surface trap.Received: 16 October 2003PACS:
32.80.Pj Optical cooling of atoms; trapping - 39.25. + k Atom manipulation (scanning probe microscopy, laser cooling, etc.) 相似文献
20.
V. Gomer O. Harms D. Haubrich H. Schadwinkel F. Strauch B. Ueberholz S. aus der Wiesche D. Meschede 《Hyperfine Interactions》1997,109(1-4):281-292
We have constructed magnetostatic traps from permanent magnets for trapping charged and neutral atoms. Two storage experiments
are presented: a compact Penning trap for light ions and magnetic trapping of single neutral atoms. The dynamics of cold neutral
atoms and their loss mechanisms in a quadrupole magnetostatic trap are discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献