检索结果-南通市图书馆

Parametric resonance and cooling on an atom chip

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2008年第3期17卷 921-926页

作者：颜波李晓林柯敏王育竹 key laboratory for quantum optics Center for Cold Atom PhysicsShanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

This paper observes the parametric excitation on atom chip by measuring the trap loss when applying a parametric modulation. By modulating the current in chip wires, it modulates not only the trap frequency but also the trap position. It shows that the strongest resonance occurs when the modulation frequency equals to the trap frequency. The resonance amplitude increases exponentially with modulation depth. Because the Z-trap is an anharmonic trap, there exists energy selective excitation which would cause parametric cooling. We confirm this effect by observing the temperature of atom cloud dropping.

关键词： atom chip parametric excitation parametric cooling

Optimal transport of cold atoms by modulating the velocity of traps

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2013年第2期22卷 232-238页

作者：韩景珊许忻平张海潮王育竹 key laboratory for quantum optics Center for Cold Atom PhysicsShanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

This work experimentally demonstrates a new method of optimizing the transport of cold atoms via modulating the velocity profile imposed on a magnetic quadrupole *** trap velocity and corresponding modulation are controlled by varying the currents of two pairs of anti-Helmholtz *** 87Rb atoms are transported in a non-adiabatic regime over 22 mm in 200 *** the transported atoms their final-vibration amplitude dependences of modulation period number,depth,and initial phase are *** modulation period n = 5,modulation depth K = 0.55,and initial phase φ = 0,cold atom clouds with more atom numbers,smaller final-vibration amplitude,and lower temperature are efficiently *** analysis and numerical simulation are also provided,which are in good agreement with experimental results.

关键词： transport of cold atoms modulation velocity profile

A grooved planar ion trap design for scalable quantum information processing

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2012年第6期21卷 172-178页

作者：冀炜邦万金银成华东刘亮 key laboratory for quantum optics and center for cold atom physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

We describe a new electrode design for a grooved surface-electrode ion trap,which is fabricated in printed-circuitboard technology with segmented *** design allows a laser beam to get through the central groove to avoid optical access blocking and laser scattering from the ion trap *** confining potentials are modeled both analytically and *** optimize the radio frequency（rf） electrodes and dc electrodes to achieve the maximum trap depth for a given ion height above the trap *** also compare our design with the reality ion chip MI I for practical *** results show that our design is superior to MI *** ion trap design may form the basis for large scale quantum computers or parallel quadrupole mass spectrometers.

关键词： ion trapping microfabrication quantum information

Optimization of polarization spectroscopy for rubidium D lines

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2013年第2期22卷 271-275页

作者：孙剑芳尹士奇徐震洪涛王育竹 key laboratory for quantum optics Center for Cold Atom PhysicsShanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences

Polarization spectroscopy of the D lines of rubidium atoms is investigated experimentally,especially with different pump powers and cell *** find that there are four candidate transitions suitable for frequency stabilization,and optimal pump powers and cell temperatures are also presented to obtain a perfect signal with maximal amplitude and *** optimal signal is insensitive to the fluctuations of laser power and the temperature,which can enhance the performance of frequency locking.

关键词： polarization spectroscopy pump power temperature

Automatic compensation of magnetic field for a rubidium space cold atom clock

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2016年第7期25卷 192-195页

作者：李琳吉经纬任伟赵鑫彭向凯项静峰吕德胜刘亮 key laboratory for quantum optics and center of cold atom physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

When the cold atom clock operates in microgravity around the near-earth orbit, its performance will be affected by the fluctuation of magnetic field. A strategy is proposed to suppress the fluctuation of magnetic field by additional coils, whose current is changed accordingly to compensate the magnetic fluctuation by the linear and incremental compensation. The flight model of the cold atom clock is tested in a simulated orbital magnetic environment and the magnetic field fluctuation in the Ramsey cavity is reduced from 17 nT to 2 nT, which implied the uncertainty due to the second order Zeeman shift is reduced to be less than 2×10^（-16）. In addition, utilizing the compensation, the magnetic field in the trapping zone can be suppressed from 7.5 μT to less than 0.3 μT to meet the magnetic field requirement of polarization gradients cooling of atoms.

关键词： laser cooling space cold atom clock magnetic field compensation

Initial Tests of a Rubidium Space cold atom Clock

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2016年第6期33卷 17-20页

作者：李琳屈求智汪斌李唐赵剑波吉经纬任伟赵鑫叶美凤姚媛媛吕德胜刘亮 key laboratory of quantum optics and center of cold atom physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

We report the initial test results of a rubidium （87Rb） space cold atom clock （SCAC）. The space-qualified ST Rb SCAC is composed of the physical package, the optical bench, the microwave synthesizer and the control electronics. After the system is integrated, about 108 ST Rb cold atoms are captured by magneto-optical trap. The linewidth of the Ramsey fringe is about lO Hz for the free evolution time of 50ms on the ground, and the signM-to-noise ratio is measured to be larger than 300. We demonstrate a good medium-term fractional frequency stability of 1.5×10^-14@1000s in the closed-loop operation on the ground. The main effects of the noise on the stability are a/so presented, and the optimized operating parameter is analyzed for the operation of SCAC in the microgravity environment.

关键词： of on in is for Rb been MOT

Continuous Imaging of a Single Neutral atom in a Variant Magneto-Optical Trap／hyperlinks

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2010年第2期27卷 80-82页

作者：夏天周蜀渝陈鹏李琳洪涛王育竹 key laboratory for quantum optics Center for Cold Atom Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800

We demonstrate continuous imaging of a single 87Rb atom confined in a steep magneto-optical trap with an electron-multiplying charge-coupled device （EMCCD） camera and realize a one-dimensional micro-optical trap array with a Dammann grating. We adopt several methods to reduce the noise in the fluorescence signal we obtain with the EMCCD. Step jumping characteristics of the fluorescence demonstrate capturing and losing of individual atoms.

关键词： atomic and molecular physics

Experimental Investigation of Quality of Lensless Ghost Imaging with Pseudo-Thermal Light

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese physics Letters 2008年第11期25卷 3968-3971页

作者：沈夏白艳锋秦涛韩申生 key laboratory for quantum optics and center for cold atom physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800

Factors influencing the quality of lensless ghost imaging are investigated. According to the experimental results, we find that the imaging quality is determined by the number of independent sub light sources on the imaging plane of the reference arm. A qualitative picture based on advanced wave optics is presented to explain the physics behind the experimental phenomena. The present results will be helpful to provide a basis for improving the quality of ghost imaging systems in future works.

关键词： the power-law exponents precipitation durative abrupt precipitation change

Narrowband Biphoton Generation with Four-Wave Mixing in a Far-Detuning Three-Level System

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese physics Letters 2011年第7期28卷 168-171页

作者： CHEN Peng ZHOU Shu-Yu XU Zhen DUAN Ya-Fan CUI Guo-Dong HONG Tao WANG Yu-Zhu key laboratory for quantum optics Center for Cold Atom PhysicsShanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800

Non-classical paired photons are generated by a four-wave mixing process in a far-detuning three-level system with cold atoms.A violation of the Cauchy–Schwartz inequality of a factor of 310 is *** phenomenon shows that paired photons have a non-classical *** experimental results are compared with theoretical results obtained using perturbation *** oscillation frequencies of the two-photon intensity correlation functions are in reasonable agreement with the effective Rabi frequencies of the coupling ***,we find that the dephasing rates(or decay rates)observed are far larger than the theoretical values.

关键词： theory photon inequality