【作者】 宫艳丽；

【导师】 萨楚尔夫；

【作者基本信息】 内蒙古师范大学 ， 光学， 2008， 硕士

【摘要】 为了进一步揭示玻色-爱因凝聚原子与二项式光场相互作用系统中的量子特性,以及运动原子与二项式光场相互作用系统的量子特性,更好的理解和应用量子信息理论,本文将量子信息论中的压缩理论、保真度理论、信息熵理论运用到光场与原子的相互作用系统。利用全量子理论、量子信息保真度理论、量子信息熵理论等方法,分别研究了玻色-爱因斯坦凝聚与二项式光场相互作用系统中的压缩特性、原子玻色-爱因斯坦凝聚与二项式光场相互作用系统的保真度以及与二项式光场相互作用的运动原子熵压缩,得到一些新结果。首先,根据二能级原子玻色-爱因斯坦凝聚体与二项式光场耦合系统的相互作用特点,讨论了二项式光场和玻色-爱因斯坦凝聚系统的耦合输出相干原子束的压缩性质。研究结果发现:二项式光场的两正交分量的涨落均可压缩,压缩程度受系统参数的影响,并且随时间呈周期性变化;BEC原子激光的两正交分量的涨落也均可压缩,改变光场与原子间的相互作用强度的情况下,原子间的相互作用不利于原子激光压缩效应的产生,若考虑存在外场作用,则外场对压缩效应将产生明显的影响。其次,通过研究玻色-爱因斯坦凝聚原子与二项式光场相互作用系统的保真度,讨论了原子间相互作用强度、处于基态时超冷原子数和光场参数的不同取值对系统保真度有影响,结果表明:通过改变原子间相互作用强度和基态原子数可以改变系统保真度的幅值和振荡周期,而光场参数的改变只影响保真效果,适当选取参量可以得到较好量子信息保真。最后,在完成前期工作的基础上,又研究了运动二能级原子与二项式光场相互作用过程中运动原子的信息熵压缩,讨论了不同原子初态和光场的有关参数对信息熵的影响,通过选择不同的原子初态、场模结构、场调节参数及原子运动速度可以调控原子信息熵的压缩方向、偶极矩分量值和压缩周期,适当的选择参数可得到持续性的原子信息熵压缩。更多还原

【Abstract】 For better disclosing the quantum properties in the system of Bose-Einstein Condensation atom and the moving atom interacting with the binomial states field respectively, and better understanding and applying the quantum information theory, the squeezing theory that contains the light field squeezed and the atomic laser squeezed, the fidelity theory of the quantum information theory, and the entropy theory to the system of atom interacting with field are discussed in this paper. The squeezing properties of the binomial states field interacting with atomic Bose-Einstein Condensate, fidelity of quantum state in a system interacting the binomial photon field with atomic Bose-Einstein Condensate and entropy squeezing in a system interacting the moving atom with the binomial light field are studied by means of the quantum squeezing theory, quantum fidelity and quantum information entropy etc.Fist, the squeezing properties of the binomial states field interacting with Bose-Einstein condensate (BEC) of two-level atoms are studied. The results indicate that one of the two qu阿drature components of light field evolve periodically with time and can be squeezed, and the system parameters influence the squeezing depth, the fluctuations of two quadrature components of the atomic laser can be squeezed alternatively as the variety of the parameter of light field interacting with atoms and the interaction among the atoms in BEC is disadvantageous to the squeezing of atomic lasers, but the atomic laser can show complete squeezing effects as the influence of light field is considered.Second, the properties of the evolution of fidelities of quantum state under the interaction of the binomial photon field and atomic Bose-Einstein condensate are studied by means of quantum fidelity. The influences of the interaction among atoms of Bose-Einstein condensate,the average atomic number of atomic BEC and the parameter of light field on the fidelity are investigated. The results indicate that the amplitude and oscillated period of fidelity of quantum information for interaction system can be controlled by choosing the intensity of the interaction among atoms the light parameter and the average atomic number on the ground state. The higher fidelity can be obtained by choosing suitable parameters.At last, the information entropy squeezing properties of the atom in motion interacting with the binomial states field via single photon transition are studied by means of quantum theory. The influences of the parameter of light field on the information entropy squeezing properties of the atom are investigated as the initial atom is in any state. The results indicate that the value of squeezed component of the atomic dipole, amplitude, squeezed time and squeezed direction of the atomic information entropy can be controlled by choosing the atomic initial state, the field structure parameter, the velocity of atomic motion. It is shown that the moving atom may exhibit the long time squeezing effect for some parameters.更多还原