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1.
We demonstrate the separation of isotopes based on quantum revival phenomenon in nanofibers. We use an optical nanofiber carrying blue-detuned light and red-detuned light. Keeping in view the detuning of atoms with the optical fields, we create attractive and repulsive potentials around the fiber in the radial direction, which produce potential minima in the transverse plane. The wave packets of differing isotopes revive at different quantum revival times and become spatially separated. 相似文献
2.
Daniel Reitz Arno Rauschenbeutel 《Optics Communications》2012,285(23):4705-4708
A double-helix optical trapping potential for cold atoms can be straightforwardly created inside the evanescent field of an optical nanofiber. It suffices to send three circularly polarized light fields through the nanofiber; two counterpropagating and far red-detuned with respect to the atomic transition and the third far blue-detuned. Assuming realistic experimental parameters, the transverse confinement of the resulting potential allows one to reach the one-dimensional regime with cesium atoms for temperatures of several μK. Moreover, by locally varying the nanofiber diameter, the radius and pitch of the double-helix can be modulated, thereby opening a realm of applications in cold-atom physics. 相似文献
3.
We propose a novel scheme to form a 2D dark optical surface lattice (DOSL) for cold atoms on the surface of the dense flint glass by using two sets of blue-detuned evanescent wave interference fields and a blue-detuned evanescent wave field. In the 2D DOSL, cold atoms will be trapped in the vicinity of minimum intensity and suffered the minimal light shift as well as the lowest coherence loss. The total potential and trap-depth of the individual optical micro-trap in the 2D DOSL are high enough to trap cold atoms (T = 120 μK) released from the standard magneto-optical trap (MOT), and atoms trapped in the 2D DOSL can be cooled to several μK with the efficient intensity-gradient Sisyphus cooling. The lattice constant of the DOSL can be controllable by changing the incident angles of lights. 相似文献
4.
D. Schrader S. Kuhr W. Alt M. Müller V. Gomer D. Meschede 《Applied physics. B, Lasers and optics》2001,73(8):819-824
Using optical dipole forces we have realized controlled transport of a single or any desired small number of neutral atoms
over a distance of a centimeter with sub-micrometer precision. A standing wave dipole trap is loaded with a prescribed number
of cesium atoms from a magneto-optical trap. Mutual detuning of the counter-propagating laser beams moves the interference
pattern, allowing us to accelerate and stop the atoms at preselected points along the standing wave. The transportation efficiency
is close to 100%. This optical ‘single-atom conveyor belt’ represents a versatile tool for future experiments requiring deterministic
delivery of a prescribed number of atoms on demand.
Received: 6 July 2001 / Published online: 23 November 2001 相似文献
5.
We propose a two-color scheme of atom waveguides and one-dimensional (1D) optical lattices using evanescent wave fields of different transverse modes around an optical micro/nano-fiber. The atom guide potential can be produced when the optical fiber carries a red-detuned light with TE01 mode and a blue-detuned light with HEll mode, and the 1D optical lattice potential can be produced when the red-detuned light is transformed to the superposition of the TE01 mode and HE11 mode. The two trapping potentials can be transformed to each other for accurately controlling mode transformation for the red-detuned light. This might provide a new approach to realize flexible transition between the guiding and trapping states of atoms. 相似文献
6.
Diffracted field distribution from a knife-edge truncated semi-Gaussian beam as an atomic (molecular) mirror
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We investigate the diffraction characteristics of an incident Gaussian
beam cut
by a straight edge bounding a semi-infinite opaque plane using Kirchhoff
scalar wave theory in the Fresnel limit, and propose a new and simple mirror
scheme to reflect atoms by using the intensity gradient induced by a
blue-detuned semi-Gaussian laser beam. The optical potential of the
diffracted light of the knife-cut semi-Gaussian beam for
$^{85}$Rb atom and its spontaneous emission probability are calculated and
compared with the performance of the evanescent-wave mirror. Our study shows
that the optical potential of the diffracted light of the semi-Gaussian beam
is far higher than that of the evanescent light wave, and the maximum normal
velocity of the incident atoms can be far greater than that of the
evanescent light wave under the same parameters, so the blue-detuned
semi-Gaussian beam, as a novel atomic mirror, can be used to efficiently
reflect cold atoms with a normal velocity of greater than 1 m/s. However,
the intensity gradient (force) of the diffracted light of the
semi-Gaussian-beam is much smaller than that of the evanescent light wave, so
its spontaneous emission probability is greater than that from the
evanescent-wave when the normal velocity of incident atoms is greater. 相似文献
7.
提出了一种采用两套超大红失谐消逝波干涉和一束蓝失谐消逝波光场来实现原子二维表面微光阱阵列和原子有效强度梯度冷却的新方案,得到了二维表面微光阱阵列的光强分布和光学势分布.研究发现,二维表面微光阱阵列中微光阱的光学势能够有效地囚禁从标准磁光阱中释放的冷原子,并且被囚禁的冷原子能在蓝失谐消逝波光场的作用下产生有效的强度梯度Sisyphus冷却,对87Rb原子而言,原子温度能被冷却到2.56μK.该方案在冷原子物理、原子光学和量子光学领域中有着广阔的应用前景.
关键词:
消逝波干涉
微光阱阵列
原子囚禁
强度梯度冷却 相似文献
8.
9.
Discrete-element simulations are performed to study particle transport by standing waves on an electric curtain. An electric curtain consists of a series of parallel electrodes with oscillating potential field embedded in a dielectric surface. The study shows that particles can be transported in two different modes under excitation by standing waves. In the first mode, particles roll along the surface in a constant direction with average velocity equal to the wave speed. In the second mode, particles hop along the surface in a manner akin to a Brownian motion. Effect of particle collisions on these transport modes is evaluated. 相似文献
10.
Adiabatic focusing of cold atoms in a blue-detuned laser standing wave is analyzed. It is shown that using repulsive light
forces that push atoms towards dark regions and thus minimizes heating, cold atoms can be adiabatically compressed by more
than an order of magnitude to yield background-free sub-10-nm (rms) spots. The optimal parameters for the atomic lens and
the maximal compression ratio are predicted using an analytic model and found to be in agreement with the exact results of
our Monte Carlo simulations. A combined adiabatic-coherent scheme is proposed and shown to yield 8.8 nm spot size even for
a thermal atomic beam.
Received: 1 October 1999 / Revised version: 13 December 1999 / Published online: 5 April 2000 相似文献
11.
12.
A Goban KS Choi DJ Alton D Ding C Lacroûte M Pototschnig T Thiele NP Stern HJ Kimble 《Physical review letters》2012,109(3):033603
We report the experimental realization of an optical trap that localizes single Cs atoms ?215 nm from the surface of a dielectric nanofiber. By operating at magic wavelengths for pairs of counterpropagating red- and blue-detuned trapping beams, differential scalar light shifts are eliminated, and vector shifts are suppressed by ≈250. We thereby measure an absorption linewidth Γ/2π=5.7±0.1 MHz for the Cs 6S_{1/2}, F=4→6P_{3/2}, F^{'}=5 transition, where Γ_{0}/2π=5.2 MHz in free space. An optical depth d?66 is observed, corresponding to an optical depth per atom d_{1}?0.08. These advances provide an important capability for the implementation of functional quantum optical networks and precision atomic spectroscopy near dielectric surfaces. 相似文献
13.
14.
基于半经典理论,分析了中性钠原子在激光驻波场中的受力特征,以此为基础分别对不同纵向运动速度和横向运动速度条件下中性钠原子的运动轨迹进行了仿真运算,得到了不同速度条件下中性钠原子的运动轨迹特征,基于累计算法进一步对不同速度条件下中性钠原子的沉积特性进行了仿真,当钠原子的纵向运动速度符合最可及速度(740 m/s)时,纳米沉积条纹的半高宽为2.78 nm,条纹对比度为38.5 ∶1,当纵向运动速度偏离最可及速度(350 m/s)时,纳米沉积条纹的半高宽为29.1 nm,其对比度下降为15 ∶1.而当中性钠原子
关键词:
原子光刻
激光驻波场
条纹半高宽
条纹对比度 相似文献
15.
Dotsenko I Alt W Khudaverdyan M Kuhr S Meschede D Miroshnychenko Y Schrader D Rauschenbeutel A 《Physical review letters》2005,95(3):033002
We optically detect the positions of single neutral cesium atoms stored in a standing wave dipole trap with a subwavelength resolution of 143 nm rms. The distance between two simultaneously trapped atoms is measured with an even higher precision of 36 nm rms. We resolve the discreteness of the interatomic distances due to the 532 nm spatial period of the standing wave potential and infer the exact number of trapping potential wells separating the atoms. Finally, combining an initial position detection with a controlled transport, we place single atoms at a predetermined position along the trap axis to within 300 nm rms. 相似文献
16.
LI Chuanwen CAI Weiquan WANG Yuzhu 《Chinese Journal of Lasers》2000,9(1):75-78
1 Introduction SinceG.Timp'sgroupobservedlightdiffractionfromchannelizedatomsin1992[1],lithographywithNa,Cr,andAlatomicbeamhasb... 相似文献
17.
After deriving the approximation solution which describes the motion of neutral atoms in an optical standing wave field with large detuning, the spherical aberration and the chromatic aberration are analyzed and possible methods to reduce these aberrations are discussed. 相似文献
18.
A.P. Kazantsev 《Optics Communications》1976,17(2):166-169
The recoil effect in a strong resonance field of a standing electromagnetic wave has been studied. In order to find the response to the external field (the induced dipole momentum) it is necessary to take into account the variations in the motion of the atoms in this field: the response and the energy spectrum of the atoms are determined from the system of wave equations for the multi-level atoms. The problem of a weak signal absorption in the presence of a strong standing wave which is in resonance with the adjacent transition, is solved. In this case the contour of the absorption line is shown to diverge into two wide bands, their width being proportional to the strong field amplitude. The contribution of continuous and discrete states of the atoms in a standing wave field has been found. 相似文献
19.
We report the experimental observation of rectified momentum transport for a Bose-Einstein condensate kicked at the Talbot time (quantum resonance) by an optical standing wave. Atoms are initially prepared in a superposition of the 0 and -2hkl momentum states using an optical pi/2 pulse. By changing the relative phase of the superposed states, a momentum current in either direction along the standing wave may be produced. We offer an interpretation based on matter-wave interference, showing that the observed effect is uniquely quantum. 相似文献