利用绝热过程制备GHZ态

提出一种利用绝热过程制备多原子GHZ态的方案.本方案可有效地抑制原子的自发辐射噪声.利用相似的方法可制备腔场GHZ态.制备成功的几率约为1.0.     

Spectroscopic properties of the molecular ions BeX+ (X=Na,K, Rb): forming cold molecular ions from an ion–atom mixture by stimulated Raman adiabatic process

In this theoretical work, we calculate potential energy curves, spectroscopic parameters and transition dipole moments of molecular ions BeX⁺ (X=Na, K, Rb) composed of alkaline ion Be and alkali atom X with a quantum chemistry approach based on the pseudopotential model, Gaussian basis sets, effective core polarisation potentials and full configuration interaction. We study in detail collisions of the alkaline ion and alkali atom in quantum regime. Besides, we study the possibility of the formation of molecular ions from the ion–atom colliding systems by stimulated Raman adiabatic process and discuss the parameters regime under which the population transfer is feasible. Our results are important for ion–atom cold collisions and experimental realisation of cold molecular ion formation.     

Production and detection of ultracold Cs2 molecules via four-photon adiabatic passage

We study theoretically how to produce and detect the ultracold ground-state Cs2molecule from Feshbach state. Numerical calculations are performed by solving the quantum Liouville equation based on multilevel Bloch model. The producing efficiency reaches 55% and the detecting efficiency is 31%. The producing and detecting efficiencies are closely related to the Rabi frequencies of laser pulses. The decay of relevant electronic and vibrational states obviously reduces the producing and detecting efficiencies.     

耗散对受激拉曼绝热转移过程的影响

应用最近发展的量子耗散理论,研究了耗散对简单三能级体系的受激拉曼绝热转移过程的影响,并与pump-dump过程比较.计算结果表明,受激拉曼绝热转移的机制能很好地抑制中间态的弛豫与涨落的影响.数值结果也表明了新的量子耗散理论可以正确地描述场与耗散相互耦合的动力学问题.     

双Λ型原子系统中制备相干叠加态的研究(英文)

本文讨论了在双Λ型原子系统中制备相干叠加态的方法:一个Λ型系统通过控制激光而另一个Λ型系统采用部分受激拉曼绝热通道的方法.在理论上分析了产生任意相干叠加态的可能性并且讨论了透热系统在产生相干叠加态过程中的重要性.研究表明,没有透热过程是不可能制备出任意的叠加态.应用数值方法验证理论分析是正确,并且指出任意叠加态的产生只与控制脉冲的时间延迟有关.     

Numerical exploration of coherent excitation in three-level ladder systems

The technique of stimulated Raman adiabatic passage (STIRAP) is used to transfer potassium atoms from the 22p state to the 21p Rydberg state through the intermediate state 22s. The results show that complete population transfer is related to pulse duration and overlap, and occurs when the pulse duration and overlap have adequate values. At the same time, population trapping is also formed. Complete population transfer can also occurs when the two-photon resonance condition ({\it\Delta}_s= {\it\Delta}_p) is met.     

耗散对受激拉曼绝热转移过程的影响

应用最近发展的量子耗散理论 ,研究了耗散对简单三能级体系的受激拉曼绝热转移过程的影响 ,并与pump dump过程比较 .计算结果表明 ,受激拉曼绝热转移的机制能很好地抑制中间态的弛豫与涨落的影响 .数值结果也表明了新的量子耗散理论可以正确地描述场与耗散相互耦合的动力学问题     

利用绝热过程制备W态

提出一种利用绝热过程制备多原子W态的方案.本方案可有效地抑制原子的自发辐射噪声.利用相似的方法可制备腔场W态.制备成功的几率约为1.0.     

基于绝热快速通道控制原子布居数及其相干性的研究

本文在理论上研究了纳秒数量级内，运用绝热快速通道（ARP）来控制基态原子的相干性及 其布居数在不同能态间的转移.理论计算结果表明抽运激光脉冲相对斯托克斯（Stokes）脉 冲延迟时间的微小改变会导致原子相干性及其布居数的显著变化.运用密度矩阵方程和麦克 斯韦方程联合的自洽方程数值解，我们找到了实现原子最大相干性及其布居数在不同能态间 完全转移的条件. 关键词： 绝热快速通道 布居数 原子相干     

Efficient weakly-radiative wireless energy transfer: An EIT-like approach

Inspired by a quantum interference phenomenon known in the atomic physics community as electromagnetically induced transparency (EIT), we propose an efficient weakly radiative wireless energy transfer scheme between two identical classical resonant objects, strongly coupled to an intermediate classical resonant object of substantially different properties, but with the same resonance frequency. The transfer mechanism essentially makes use of the adiabatic evolution of an instantaneous (so called “dark”) eigenstate of the coupled 3-object system. Our analysis is based on temporal coupled mode theory (CMT), and is general enough to be valid for various possible sorts of coupling, including the resonant inductive coupling on which witricity-type wireless energy transfer is based. We show that in certain parameter regimes of interest, this scheme can be more efficient, and/or less radiative than other, more conventional approaches. A concrete example of wireless energy transfer between capacitively-loaded metallic loops is illustrated at the beginning, as a motivation for the more general case. We also explore the performance of the currently proposed EIT-like scheme, in terms of improving efficiency and reducing radiation, as the relevant parameters of the system are varied.