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冷原子介质中光学双稳态和多稳态的半经典理论研究

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冷原子介质中光学双稳态和多稳态的半经典理论研究

作者：吕新友华中科技大学

学位级别：硕士

光学双稳态和多稳态是量子光学和非线性光学中的一个十分重要的研究课题,由于其在光晶体管、光存储、光开关等方面的广泛应用,人们已经分别从实验上和理论上对其展开了大量的研究。特别是冷原子介质中的电磁感应透明(EIT)效应被广泛关... 详细信息

光学双稳态和多稳态是量子光学和非线性光学中的一个十分重要的研究课题,由于其在光晶体管、光存储、光开关等方面的广泛应用,人们已经分别从实验上和理论上对其展开了大量的研究。特别是冷原子介质中的电磁感应透明(EIT)效应被广泛关注以来,人们对冷原子介质中光学双稳态和多稳态现象的半经典理论研究也随之增多。本论文主要是运用了半经典理论对四能级冷原子介质中的光学双稳态和多稳态现象进行了理论研究。具体来说,本论文的主要工作分为以下几个部分:;(1)阐述了两束激光与三能级冷原子介质相互作用的半经典理论。 (2)研究了典型四能级冷原子介质中的光学双稳态行为,并分析和讨论了在此系统中出现一个额外相干项——自发生成相干(SGC)项的情况下,探测场光学双稳态的行为特性。还分析了控制场强度,控制场与探测场的相对初位相及SGC效应对双稳态行为的影响。 (3)在封闭型四能级冷原子介质中,讨论和分析了探测场的光学双稳态和多稳态特性。提出了一种实现光学双稳态与多稳态之间相互转换的理论方案,同时研究了光学多稳态现象出现的条件。 (4)在N型冷原子介质中,提出一种简单地实现探测场光学多稳态的理论方案,并讨论了控制场的强度及频率失谐对光学双稳态和多稳态行为的影响。

关键词：光学双稳态光学多稳态自发生成相干电磁感应透明阈值回滞圈

Exact analytical solutions to the mean-field model depicting microcavity containing semiconductor quantum wells

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Chinese Physics B 2010年第5期19卷 85-91页

作者：宋佩君吕新友刘继兵郝向英 School of Physics and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Department of Physics Hubei Normal University

By using a two-mode mean-field approximation, we study the dynamics of the microcavities containing semiconductor quantum wells. The exact analytical solutions are obtained in this study. Based on these solutions, we show that the emission from the microcavity manifests periodic oscillation behaviour and the oscillation can be suppressed under a certain condition.

关键词： mean-field model microcavity exact analytical solutions

Controllable Optical Bistability and Multistability in a Four-Level Atomic System with Closed-Loop Configuration

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Chinese Physics Letters 2007年第1期24卷 108-111页

作者：吕新友李家华刘继兵 Department of Physics Huazhong University of Science and Technology Wuhan 430074

We theoretically investigate optical bistability （OB） and multistability （OM） behaviour of a closed-loop configuration atomic system driven by a degenerate coupling- field and a degenerate probe field inside a unidirectional ring cavity. It is found that the OB and OM behaviour can be controlled by adjusting- the intensity and the frequency detuning of the coupling- field, respectively. Interestingly, our numerical results show that it is easy to realize the transition from OB to OM or vice versa by adjusting- the intensity of the coupling- field under a appropriate frequency detuning. The effect of the atomic cooperation parameter on the OB behaviour is also discussed.

关键词： Atomic System Multistability Closed-Loop Configuration optical bistability (OB) multistability (OM)

Deterministic generation of Greenberger-Horne-Zeilinger and W states for three distant atoms via adiabatic passage

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Chinese Physics B 2011年第5期20卷 80-90页

作者：宋佩君吕新友司留刚杨晓雪 School of Physics and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology School of Physics Ludong University

We propose two schemes for generating Greenberger-Horne-Zeilinger and W states of three distant atoms. In the present schemes, the atoms are individually trapped in three spatially separated optical cavities coupled by two optical fibres. Performing an adiabatic passage along dark states, the population of cavities and fibres excited is negligible under certain conditions. In addition, the spontaneous decay of atoms is also efficiently suppressed based on our proposals. Furthermore, the discussion about the entanglement fidelity is given and we point out that our schemes work robustly with small fluctuations of experimental parameters.

关键词： Greenberger-Horne-Zeilinger state W state adiabatic passage

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金属矿石的激发极化非线性谱特征

物探与化探 1991年第5期15卷 358-365页

作者：吕新友傅良魁中国地质大学.北京

通过对石墨、铜及若干个金属矿区的矿石标本进行实验研究，系统地观测了它们的时间谱和电流谱。根据实验结果，标本的时间谱和电流谱的阴、阳极优势情况有两种基本类型。以电化学理论为基础，对产生这两种基本类型的机理作出了解释，认... 详细信息

通过对石墨、铜及若干个金属矿区的矿石标本进行实验研究，系统地观测了它们的时间谱和电流谱。根据实验结果，标本的时间谱和电流谱的阴、阳极优势情况有两种基本类型。以电化学理论为基础，对产生这两种基本类型的机理作出了解释，认为这与标本的可溶性与否有关。在一定条件下，根据谱的阴、阳极优势情况识别极化体的可溶性和不可溶性是可能的。

关键词：金属矿矿石激发极化法谱非线性

Tripartite Entanglement via Microwave Driven Atomic Coherence

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Chinese Physics Letters 2010年第4期27卷 45-48页

作者：金丽霞吕新友宋佩君杨晓雪 School of Physics Huazhong University of Science and Technology Wuhan 430074 chool of Physics Ludong University Yantai 264025

We propose a new scheme to achieve the tripartite entanglement based on the standard criteria [Phys. Rev. A 67（2003） 052315] in a inverse-tripod atomic system. In our scheme, the atomic coherence is introduced by two microwave fields which drive the upper three levels of atom. By numerically simulating the dynamics of system, we investigate the generation and evolution of entanglement in the presence of atom and cavity decay. As a result, the present research provides an efficient approach to achieve fully tripartite entanglement with different frequencies and initial states for each entangled mode, which may have impact on the progress of multicolored multi-notes quantum information networks.

关键词： Computational physics Optics quantum optics and lasers Quantum information and quantum mechanics

Non-Adiabatic Geometric Phase in a Dispersive Interaction System

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Chinese Physics Letters 2007年第5期24卷 1136-1139页

作者：刘继兵李家华吕新友郑安寿 Department of Physics Huazhong University of Science and Technology Wuhan 430074 Department of Mathematic and Physics China University of Geosciences Wuhan 430074

We investigate the geometric phase and dynamic phase of a two-level fermionic system with dispersive interaction, driven by a quantized bosonic field which is simultaneously subjected to parametric amplification. It is found that the geometric phase is induced by a counterpart of the Stark shift. This effect is due to distinct shifts in the field frequency induced by interaction between different states （｜e〉 and ｜g〉） and cavity field, and a simple geometric interpretation of this phenomenon is given, which is helpful to understand the natural origin of the geometric phase.

关键词： SCHRODINGER-CAT STATES MAGNETIC-RESONANCE ELECTROMAGNETIC-FIELD MIXEDSTATES BERRY PHASE TRAPPED ION SHIFT MODEL

Deterministic Generation of Quantum State Transfer Between Spatially Separated Single Molecule Magnets

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Communications in Theoretical Physics 2010年第8期54卷 278-286页

作者：宋佩君吕新友黄培郝向英杨晓雪 School of Physics and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology

We propose a new scheme for realizing deterministic quantum state transfer （QST） between two spatially separated single molecule magnets （SMMs） with the framework of cavity quantum eleetrodynamics （QED）. In the present scheme, two SMMs are trapped in two spatially separated optical cavities coupled by an optical fiber. Through strictly numerically simulating, we demonstrate that our scheme is robust with respect to the SMMs＇ spontaneous decay and fiber loss under the conditions of dispersive SMMs-field interaction and strong coupling of cavity fiber. In addition, we also discuss the influence of photon leakage out of cavities and show that our proposal is good enough to demonstrate the generation of QST with high fidelity utilizing the current experimental technology. The present investigation provides research opportunities for realizing QST between solid-state qubits and may result in a substantial impact on the progress of solid-state-based quantum communications network.

关键词： quantum state transfer cavity QED single molecule magnet

Holographic Laser as a Source of Continuous Variable Entanglement

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Chinese Physics Letters 2010年第1期27卷 25-28页

作者：杨斌吕新友吴梦溪 School of Physics Huazhong University of Science and Technology Wuhan 430074 Department of Physics Southeast University Nanjing 210096

We study the generation and evolution of continuous-variable entanglement in a holographic laser. The two-level atomic medium is trapped in a ring cavity, and couples with two counter-propagating modes. By simulating the dynamics of the system, our numerical results show that the two-mode continuous variable （CV） entanglement can be realized in the present system even in the presence of cavity loss. This investigation provides a research clue for realizing CV entanglement in a two-level atomic medium, which is simpler than the previous works.

关键词： Chinese climate network complex systems small world community