Partial teleportation of entangled atomic states

In this Letter we propose a scheme for partially teleporting entangled atomic states. Our scheme can be implemented using only four two-level atoms interacting either resonantly or off-resonantly with a single cavity-QED. The estimative of losses occurring during this partial teleportation process is accomplished through the phenomenological operator approach technique.     

Partially autoionizing states of atomic oxygen

The Rydberg states 3d′ ³P_2,^o₁, ₀ and ³s″ ³P_2,^o₁, ₀ and the inter-shell transition 2sp⁵³P_2,⁰₁, ₀, which are forbidden to autoionize on the basis of LS coupling, have been observed in emission spectroscopy and in autoionization spectra produced in the photoelectron spectrum of atomic oxygen.     

Lamb shift of laser-dressed atomic states

We discuss radiative corrections to an atomic two-level system subject to an intense driving laser field. It is shown that the Lamb shift of the laser-dressed states, which are the natural state basis of the combined atom-laser system, cannot be explained in terms of the Lamb shift received by the atomic bare states which is usually observed in spectroscopic experiments. In the final part, we propose an experimental scheme to measure these corrections based on the incoherent resonance fluorescence spectrum of the driven atom.     

Resonance spectroscopy of gravitational states of antihydrogen

We study a method to induce resonant transitions between antihydrogen ( \(\bar {H}\) ) quantum states above a material surface in the gravitational field of the Earth. The method consists in applying a gradient of magnetic field which is temporally oscillating with the frequency equal to a frequency of a transition between gravitational states of antihydrogen. Corresponding resonant change in a spatial density of antihydrogen atoms can be measured as a function of the frequency of applied field. We estimate an accuracy of measuring antihydrogen gravitational states spacing and show how a value of the gravitational mass of the \(\bar {H}\) atom can be deduced from such a measurement.     

Vacuum polarization for atomic quasienergy states

Vacuum polarization for an atomic system in the laser field is considered in the representation of quasienergy states as a radiation correction to the quasienergy. It is shown that laser effects are absent in the polarization fermion loop in case of resonant mixing of atomic levels. Perspectivity of investigation of laser effects in vacuum polarization of muonic atoms is discussed.     

Intrinsic states in atomic shell theory

The use of intrinsic states to resolve multiplicity difficulties in nuclear shell theory has been extended to the atomic case. If Slater determinantal product states are cast in the role of intrinsic states, it is often possible to produce final states that approximate to the physical states better than those determined by the group-theoretical procedures of Racah. The standard multiplicity separations for electrons of various azimuthal quantum numbersl can also be reproduced in many cases by a judicious choice of an intrinsic state. The usefulness of the method is limited principally by the fact that orthogonal intrinsic states do not necessarily yield orthogonal final states.     

Generation of atomic Greenberger-Horne-Zeilinger states and cluster states through cavity-assisted interaction

This paper proposes a scalable scheme to generate n-atom GHZ states and cluster states by using the basic building block, i.e., a weak coherent optical pulse [α） being reflected successively from a single-atom cavity. In the schemes, coherent state of light is used instead of single photon source, homodyne measurement on coherent light is done kastead of single photon detection, and no need for individually addressing keeps the schemes easy to implement from the experimental point of view. The successful probabilities of our protocols approach unity in the ideal case.     

Variational method for excited atomic states

An analysis is presented of the extremum properties of energy functionals for the excited states of many-electron systems, in particular, atoms, in the case when there exist low-lying states of the same symmetry as the excited state under consideration. Two theorems are proved concerning the relationship between the upper bound on the eigenvalues corresponding to the excited states and the extremum properties of the energy functional determined by variational test functions which depend on parameters. In this context, different variants of the one-electron approximation used in the excited-state calculations are considered: the method of obtaining self-consistent solutions with one-electron functions orthogonal within the configurations (the Hartree-Fock method for configurations); the frozen atomic core approximation for the excited configuration; the method of nonorthogonal orbitals in the excited configuration; and the approximation of the frozen ionic core. Cases are identified and reasons given for the possible collapse of the excited state energy level to an unjustifiably low value of the energy.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 18–33, August, 1990.     

原子相干态中的压缩现象

计算表明,与场的相干态类似的原子相干态,具有不同于场的相干态的压缩行为;进一步证明:直接类比于(?)(ξ)不能得到“原子压缩算符”.     

Correspondence between generalized binomial field states and coherent atomic states

We show that the N-photon generalized binomial states of electromagnetic field may be put in a bijective mapping with the coherent atomic states of N two-level atoms. We exploit this correspondence to simply obtain both known and new properties of the N-photon generalized binomial states. In particular, an over-complete basis of these binomial states and an orthonormal basis are obtained. Finally, the squeezing properties of generalized binomial state are analyzed.     

Excited states of muonium in atomic hydrogen

Muonium formation in excited states in muon-hydrogen charge-exchange collision is investigated using a method developed in a previous paper. Differential cross-section results are found to resemble positronium formation cross-section results of positron—hydrogen charge-exchange problem. Forward differential and integrated cross-sections are computed for muon energy of 2 keV and higher. Total muonium formation cross-sections are computed using Jackson and Schiff scaling rules. Muonium formation cross-section results obtained from proton—hydrogen charge-exchange cross-section results, using velocity scaling are compared with the results of the present calculation     

Measuring photoionization cross-sections of excited atomic states

A new method of photoionization cross-section measurement based on the observation of saturation in the ion yield as a function of radiation intensity has been proposed. The photoionization cross-sections for the 6²P_1/2 and 6²P_3/2 levels of Rb atoms of the fundamental and second harmonics of ruby laser radiation are measured, with a tunable pulsed dye laser used for excitation. The following values of cross-sections are obtained: (1.7±0.4)·10⁻¹⁷ cm² and (1.5±0.4)·10⁻¹⁷ cm² for the levels 6²P_3/2 and 6²P_1/2, respectively, ionized by radiation of v₂=14403 cm⁻¹, and (1.9±0.5)·10⁻¹⁷ cm² for the 6²P_3/2 level ionized by v₂=28806 cm⁻¹ radiation.     

Excited states of deformable even-even atomic nuclei

A method of calculating the collective excited states of even-even atomic nuclei is proposed. A formula depending on three parameters appropriate for calculating the energy ratios of the excited states of deformed and spherical nuclei as well as those in the intermediate region is obtained.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 19–24, November, 1972.     

Efimov states in asymmetric three-body atomic clusters

The work is devoted to the investigation of the weakly bound three-body atomic clusters. The calculations on the van der Waals trimer ⁷Li⁴He₂ are carried out using the differential Faddeev equations, which allows us to give accurate binding energies for both the ground and the exited state of the system. The results obtained indicate the Efimov nature of the excited state in this system.     

Resonance interaction of optical phonons with localized states

The optical-phonon Green’s function averaged over the positions of defects—both point and line— is calculated with allowance for possible localized states near the boundary of the continuous spectrum and for their intrinsic damping. The frequency-transfer dependence of the cross section for Raman scattering is calculated with the aid of this Green’s function.     

Manipulating atomic states via optical orbital angular-momentum

Optical orbital angular-momentum (OAM) has more complex mechanics than the spin degree of photons, and may have a broad range of application. Manipulating atomic states via OAM has become an interesting topic. In this paper, we first review the general theory of generating adiabatic gauge field in ultracold atomic systems by coupling atoms to external optical fields with OAM, and point out the applications of the generated adiabatic gauge field. Then, we review our work in this field, including the generation of macroscopic superposition of vortex-antivortex states and spin Hall effect (SHE) in cold atoms.      

碱土金属原子激光的共振辐射俘获效应

根据Holstein理论研究了碱土金属原子激光中的共振辐射俘获效应，分别计算了Ca，Sr和Ba蒸气激光在不同半径时产生共振辐射俘获效应的阈值温度、基态粒子数密度和共振能级的有效寿命.发现计算得到的阈值温度与实验报道的开始产生激光的工作温度一致，表明共振辐射俘获效应是这类激光形成粒子数反转的一个重要机制. 关键词： 共振辐射俘获 碱土金属原子激光 阈值温度     

Manipulating atomic states via optical orbital angular-momentum

Optical orbital angular-momentum (OAM) has more complex mechanics than the spin degree of photons, and may have a broad range of application. Manipulating atomic states via OAM has become an interesting topic. In this paper, we first review the general theory of generating adiabatic gauge field in ultracold atomic systems by coupling atoms to external optical fields with OAM, and point out the applications of the generated adiabatic gauge field. Then, we review our work in this field, including the generation of macroscopic superposition of vortex-antivortex states and spin Hall effect (SHE) in cold atoms.