各向异性量子点单光子发射的高偏振度特性

研究了线偏振脉冲光场激发下,单个各向异性InGaAs量子点的高偏振光发射. 给出其偏振因子与两个正交本征态之间的交叉弛豫之间的关系式. 分析表明，交叉弛豫随激发场强度增大，并导致偏振因子随激发场入射脉冲面积减小. 关键词： 量子点 单光子发射 偏振度     

Scaled-energy spectroscopy of a ｜M｜= 1 Rydberg barium atom in an electric field

We observe strong energy-dependent quantum defects in the scaled-energy Stark spectra for |M| = 1 Rydberg states of barium atoms at three scaled energies: ε = 2.000,ε = 2.500 and ε = 3.000.In an attempt to explain the observations,theoretical calculations of closed orbit theory based on a model potential including core effect are performed for non-hydrogenic atoms.While such a potential has been uniformly successful for alkali atoms with a single valence electron,it fails to match experimental results for barium atoms in the 6snp Rydberg states with two valence electrons.Our study points out that this discrepancy is due to the strong perturbation from the 5d8p state,which voids the simple approximation for constant quantum defects of principle quantum number n.     

Atomic Interferometric Gravitational-Wave Space Observatory(AIGSO)

We propose a space-borne gravitational-wave detection scheme, called atom interferometric gravitationalwave space observatory(AIGSO). It is motivated by the progress in the atomic matter-wave interferometry, which solely utilizes the standing light waves to split, deflect and recombine the atomic beam. Our scheme consists of three drag-free satellites orbiting the Earth. The phase shift of AIGSO is dominated by the Sagnac effect of gravitational-waves, which is proportional to the area enclosed by the a√tom interferometer, the frequency and amplitude of gravitational-waves.The scheme has a strain sensitivity 10~(-20)/Hz~(1/2) in the 100 mHz–10 Hz frequency range, which fills in the detection gap between space-based and ground-based laser interferometric detectors. Thus, our proposed AIGSO can be a good complementary detection scheme to the space-borne laser interferometric schemes, such as LISA. Considering the current status of relevant technology readiness, we expect our AIGSO to be a promising candidate for the future space-based gravitational-wave detection plan.     

基于原子干涉仪的微观粒子弱等效原理检验

等效原理是广义相对论的两个基本假设之一,也是爱因斯坦对弱等效原理的推广.目前,大量实验证明弱等效原理在一定的实验精度内是成立的.将引力与标准模型统一起来的新理论都要求弱等效原理破缺,因此更高精度的弱等效原理检验具有重要的科学意义.本文介绍了原子干涉仪的原理,回顾了利用原子干涉仪开展微观粒子弱等效原理检验实验研究的历史和现状,介绍了双组分原子干涉仪检验弱等效原理实验涉及的振动噪声抑制、拉曼光移频与相位噪声抑制、四波双衍射拉曼跃迁原子干涉、信号探测与数据处理等关键问题及研究进展,分析了高精度微观粒子弱等效原理检验研究的发展趋势,介绍了长基线原子干涉仪、空间原子干涉仪、超冷原子源以及纠缠原子源制备等方面的研究动态,展望了微观粒子弱等效原理检验研究的发展前景.     

Directly Trapping Atoms in a U-Shaped Magneto-Optical Trap Using a Mini Atom Chip

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.     

纠缠播送与解纠缠

近年来,人们发现在量子信息领域存在的许多的"no-going"理论.在研究纠缠的产生的同时也开始研究解纠缠.     

平移压缩Fock态下无耗散介观电感耦合电路的量子效应

研究了在平移压缩Fock态下介观电感耦合电路中电荷和电流的量子涨落.结果表明:每个回路中电荷、电流的量子涨落只依赖于两回路的器件参量和压缩参量,而与平移参量无关.     

Photoassociation of Atomic BEC within Mean-Field Approximation： Exact Solutions

We propose an exactly solvable method to study the coherent two-colour photoassociation of an atomic Bose- Einstein condensate, by linearizing the bilinear atom-molecule coupling, which allows us to conveniently probe the quantum dynamics and statistics of the system. By preparing different initial states of the atomic condensate, we can observe very different quantum statistical properties of the system by exactly calculating the quadrature- squeezed and mode-correlated functions.     

Experimental investigation of barium spectra in crossed electric and magnetic fields

This paper has studied the barium spectra in external magnetic and electric fields on the recently-built system based on a super-conducting solenoid with high stability of better than 1 Gauss. Firstly, we compared the spectra in a high pure magnetic field of $B=4.00000$\,T for different polarized laser, $\sigma^{+}$ and $\sigma^-$. We prove that after a proper shift, the $\sigma^+$ and $\sigma^-$ spectra are completely identical. We also investigated the dependence of the spectral feature in the high magnetic field on an additionally applied crossing electric field. Along with the increase of the electric field, there is an energy shift for every spectral line. Based on a transformative Hamiltonian, we explained this energy shift well.     

平移压缩Fock态下介观电容耦合电路的量子涨落

从经典电容耦合电路的运动方程出发,研究了在平移压缩Fock态下介观电容耦合电路中每个回路的电荷和电流的量子涨落.结果表明,每个回路中电荷、电流的量子涨落只依赖于两个回路的器件参数和压缩参量,而与平移参量无关. 关键词： 介观电路 电容耦合 平移压缩Fock态 量子涨落