Higher-Order Squeezing for Atomic Dipole of a Three-Level Atom in the Kerr-Like Medium Cavity Fields

In this paper, evolution of the higher order squeezing for atomic dipole of three level atom in the Kerr like medium is investigated. The atom discussed has two configurations and is driven by the single mode coherent state field. Our results show that the squeezing effects are clearly influenced by nonlinear parameters, the initial atom state and the detuning.

A sensitive detection of high Rydberg atom with large dipole moment

We report a sensitive detection of high Rydberg atom with large dipole moment utilizing its deflection near a pair of parallel cylindrical copper rods which are oppositely charged. When the low-field seeking state Rydberg atoms fly across the gradient electric field formed by the pair of rods, they will be pushed away from the rods while the high-field seeking state ones will be attracted towards the rods. These atoms will form different patterns on an ion imaging system placed downwards at the end of the rods. The spatial distribution of the deflected atoms on the imaging system is also simulated, in good agreement with the experimental results, from which we can deduce the quantum state information of the excited atoms. This state resolvable Rydberg atom detection can be used for the dynamics research of the dipole-dipole interaction between atoms with large dipole moments.

Simulation of anyons by cold atoms with induced electric dipole moment

We show that it is possible to simulate an anyon by a trapped atom which possesses an induced electric dipole moment in the background of electric and magnetic fields in a specific configuration.The electric and magnetic fields we applied contain a magnetic and two electric fields.We find that when the atom is cooled down to the limit of the negligibly small kinetic energy,the atom behaves like an anyon because its angular momentum takes fractional values.The fractional part of the angular momentum is determined by both the magnetic and one of the electric fields.Roles electric and magnetic fields played are analyzed.

Exploring the effect of aggregation-induced emission on the excited state intramolecular proton transfer for a bis-imine derivative by quantum mechanics and our own n-layered integrated molecular orbital and molecular mechanics calculations

We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.

Effect of a Magnetic Field on an Atomic Orbital

We consider the effect of a magnetic field on the motion of an atomic electron in its orbit. The usual treatment deals with the change in magnetic dipole moment assuming the electron's speed changes but the radius of its orbit remains unchanged. We derive the change in the magnetic dipole moment allowing both the speed and the radius to change. The cases of fixed radius on one hand and of fixed speed on the other are treated as special cases of our general case.

Dynamic Behaviors of Coupled Three-Level Atom System Interactingwith Light Field in Cavity Filled with Kerr-Like Medium

The Hamiltonian of coupled three-level atoms interacting with light field in the cavity filled with Kerr-like medium is derived. A simplified analytic solution to the Schrodinger equation of the system is obtained. The case of A type atom with degenerate lower levels is discussed in detail. It is shown that the coupling strength between atoms and Kerr coefficient affect the system＇s dynamic behaviors, especially the modulation period and oscillation frequency of the squeezing parameters of the field and the collective dipole moment. Dynamic behaviors of the system are sensitive to the initial state of atoms.

Resonance-Radiation Force Exerted by a Circularly Polarized Light on an Atomic Wave Packet

We study the behaviour of an atomic wave packet in a circularly polarized light, and especially give the calculation of the radiative force exerted by the circularly polarized light on the atomic wave packet under the resonance condition. A general method of the calculation is presented and the result is interesting. For example, under the condition that the wave packet is very narrow or/and the interaction is very strong, no matter whether the atom is initially in its ground state or excited state, as time approaches to infinity, the resonance-radiation force exerted by the light on the atom approaches to zero. If the atom is initially in its ground state and excited state with the probability 1/2 respectively, and if the momentum density is a even function, then the resonance-radiation force exerted by the light on the atom is equal to zero.

A significantly enhanced magnetic moment due to an electric dipole moment

We demonstrate via first-principle calculations based on the density functional theory that the magnetic moment of a helium atom under a given magnetic field has a positive correlation with the electric dipole moment when an external electric field is applied to the system.Our calculation shows that the enhancement of the magnetic moment is significant due to the reduction of the triplet-singlet splitting.We argue that this finding can be generalized to organic molecules,especially to macromolecules where the structure induced an electric dipole moment which may give rise to significantly enhanced responses to the external magnetic field.These results suggest that considerable magnetic responses prevail,particularly in bio-molecules without an inversion center.

Intrinsically asymmetric atomic character regulates piezoelectricity in two-dimensional materials

Decreasing of layer thickness causes the decrease of polarization until it disappears due to the existence of depolarization field.Therefore,the search for strong piezoelectric materials is highly desirable for multifunctional ultra-thin piezoelectric devices.Herein,we propose a common strategy for achieving strong piezoelectric materials through the electronic asymmetry induced by the intrinsically asymmetric atomic character of different chalcogen atoms.Accordingly,in the tetrahedral lattice structures,for example,M4X3Y3(M=Pd/Ni,X/Y=S,Se or Te,X≠Y)monolayers are proved to display excellent out-of-plane piezoelectricity.Ni4Se3Te3 possesses the largest piezoelectric coefficient d33 of 61.57 pm/V,which is much larger than that of most 2D materials.Enhancing the electronic asymmetry further increases the out-of-plane piezoelectricity of Janus M4X3Y3 materials.Correspondingly,the out-of-plane piezoelectricity is positively correlated with the ratio of electronegativity difference(Red)and the electric dipole moment(P).This work provides alternative materials for energy harvesting nano-devices or self-energized wearable devices,and supplies a valuable guideline for predicting 2D materials with strong out-of-plane piezoelectricity.

Nanoscale displacement of the image of an atomic source of radiation

Light emitted by an atomic source of radiation appears to travel along a straight line （ray） from the location of the source to the observer in the far field. However, when the energy flow pattern of the radiation is resolved with an accuracy better than an optical wavelength, it turns out that the field lines are usually curved. We consider electric dipole radiation, a prime example of which is the radiation emitted by an atom during an electronic transition, and we show that the field lines of energy flow are in general curves. Near the location of the dipole, the field lines exhibit a vortex structure, and in the far field they approach a straight line. The spatial extension of the vortex in the optical near field is of nanoscale dimension. Due to the rotation of the field lines near the source, the asymptotic limit of a field line is not exactly in the radially outward direction and as a consequence, the image in the far field is slightly shifted. This sub-wavelength displacement of the image of the source should be amenable to experimental observation with contemporary nanoscale-precision techniques.

纠缠原子与光场作用体系的压缩特性

研究了Kerr介质中初始处于纠缠态的两二能级原子与相干光场相互作用体系的压缩特性。通过数值计算,讨论了原子偶极间相互作用耦合常数和Kerr介质与单模腔场相互作甩的耦合强度对体系中的双原子偶极压缩和光场压缩的影响。结果发现在弱光场情况下,纠缠态原子偶极间相互作用和Kerr介质与光场作用越强,都使原子偶极振幅压缩现象从压缩状态退缩到无压缩状态;在强光场情况下,纠缠态原子偶极间相互作用越强,光场振幅压缩次数增多、振荡频率变慢; Kerr介质与光场作用越强,光场振幅压缩次数减少、振荡频率变快。

大港常压渣油各组分平均偶极矩的研究

将大港常压渣油利用液相色谱法分成六个组分,测定了各组分的平均偶极矩。结果表明,渣油分子具有极性,饱和分和轻芳烃组分、重芳烃、轻胶质、中胶质、重胶质、沥青质的偶极矩依次增大,分别为1.19、2.88、3.79、4.92、6.36、11.70 Debye。元素分析表明,从饱和分和轻芳烃组分到沥青质组分,H/C原子比逐渐下降,表明H/C原子比减小与平均偶极矩增大有关;从饱和分和轻芳烃组分到沥青质组分,S/C、N/C原子比总体呈现上升趋势,渣油组分的杂原子含量与其极性有一定的关系,但两者并不完全一致,渣油组分分子的平均偶极矩还受到其他因素的影响。

两纠缠原子与相干态光场相互作用的动力学

采用时间演化算符和数值计算方法,研究了两全同二能级纠缠原子与相干态光场相互作用的动力学,结果表明:原子布居和偶极压缩特性与两原子体系纠缠度和相干态光场强度相关联。

级联三能级原子的偶极振幅平方压缩

本文在文献［４］的基础上，定义了三能级原子的偶极振幅平方算符，进而由海森伯测不准关系，提出了三能级原子的偶极振幅平方压缩．研究了与关联双模压缩真空场作用的级联三能级原子的偶极振幅平方压缩效应．通过数值计算，讨论了初始压缩光场的压缩参数、单光子失谐量以及原子—光场耦合强度对原子偶极振幅平方压缩的影响．

量子拍频三能级原子的偶极压缩效应

本文讨论V型量子拍频三能级原子体系与单模光场相互作用时原子的动力学行为，并研究了原子的偶极压缩效应。

与关联双模辐射场作用的级联三能级原子的偶极压缩效应

研究了与关联双模压缩真空场作用的级联三能级原子的偶极压缩效应。通过数值计算 ,讨论了初始压缩光场的压缩参数、单光子失谐量以及原子—光场耦合强度对原子偶极压缩的影响。

高Q Kerr介质腔内强相干光场与A型三能级原子相互作用中原子的偶极压缩效应

研究了处于高Q Kerr介质腔中强相干光场与A型三能级原子相互作用中原子的偶极压缩。着重讨论了Kerr介质、原子与光场间的耦合系数以及失谐量对原子偶极压缩的影响。

Fock态腔场与Bell态原子相互作用的动力学特性

采用时间演化算符和数值计算方法,研究了Fock态腔场与两个完全相同的二能级Bell态原子在偶极共振作用下的原子布居和偶极压缩的时间演化特性,并以此来甄别部分Bell态。

广义克尔介质对双模压缩真空场与原子相互作用系统原子量子特性的影响

运用全量子理论，研究了存在广义克尔介质时，双模压缩真空场与二能级原子相互作用系统中原子布居数的时间演化和原子的偶极压缩效应，着重讨论了广义克尔介质与双模压缩真空场作用的耦合强度Ｘ，失谐量Ω以及广义克尔介质的非线性阶数ｍ对原子行为的影响．

原子运动和场模结构对原子动力学特性的影响

研究了双光子 Jaynes-Cummings( J-C)模型中原子的动力学特性 ,讨论了在不同初态下 ,原子运动和场模结构对体系中原子反转的演化特性及原子偶极矩 k阶压缩的影响 .研究结果表明 ,原子的动力学特性不仅决定于原子和场的初态参量 ,而且通过时间因子 gΘ( t) =2 - 1gt-( 4p) - 1sin( 2 pgt)