Remote quantum mechanical detection of gravitational radiation

The presumed existence of atomic hydrogen in the vicinity of sources of gravitational radiation suggests its use as a radiation detector. Curvature-induced atomic energy level shifts carry a unique signature and could thus provide for remote detection of gravitational radiation. We investigate the shifts induced by space-time curvature arising from gravitational waves. The effect is studied for both low-lying and highly excited states of atomic hydrogen. Numerical results are quoted for radiation from various sources, including binary star systems, binary neutron stars, binary black holes, collapsing stars, and pulsars. In addition, we provide a theoretical upper limit to the magnitude of the effect. For completeness, we examine the shifts induced in a harmonic oscillator as well as a rigid rotator.     

Shift and Broadening of Atomic Circular States Induced by the Thermal Radiation

Optics and Spectroscopy - Analytical expressions for spontaneous and induced by blackbody radiation energy shifts and widths of atomic circular states are derived. The features of asymptotic...     

Dynamic spectral filter

Results of the discussions with N.B. Delone on the perturbation of the atomic transition by a strong nonresonant noise field of electromagnetic radiation are presented. Four examples that are conceptually and mathematically close to each other are considered: spectrum of radiation with the diffusion of phase, spectrum of radiation with the sine phase modulation, atomic absorption lineshape in the presence of a strong nonresonant noise field, and the spectral filter whose maximum-transmission frequency is varied with time (dynamic spectral filter). For all of the examples, the counterintuitive scenario of the formation of the resulting spectrum is demonstrated: the instantaneous radiation frequencies (or the instantaneous positions of the perturbed level) are not summarized in the output spectrum. The analysis is based on the limitation that is typical of the Fourier transform and lies in the fact that significant time is needed for the observation of small frequency shifts.     

Analytical expressions of non-relativistic static multipole polarizabilities for hydrogen-like ions

Analytical formulas for the static multipole polarizabilities of hydrogen-like ions are derived by using the analytical wave functions and the reduced Green function and by applying a numerical fitting procedure.Our results are then applied to the studies of blackbody radiation shifts to atomic energy levels at different temperatures.Our analytical results can be served as a benchmark for other theoretical methods.     

On a thin structure of atomic spectra in an intense resonance electromagnetic field

The interaction of an atom with an intense resonance radiation field is considered. Quasi-energy levels are found which can differ essentially from the usual thin structure of atomic levels at moderate intensities. Spontaneous emission of such a system is considered and the interaction of an atom with a depolarized field is investigated in detail. In the latter case some specific shifts and broadening of emission or absorption lines depending essentially on the polarization and coherence of the resonance field are predicted.     

Role of the multipolar black-body radiation shifts in the atomic clocks at the 10−18 uncertainty level

We present here an overview of the role of the multipolar black-body radiation (BBR) shifts in the single ion atomic clocks to appraise the anticipated 10^?18 uncertainty level. With an attempt to use the advanced technologies for reducing the instrumental uncertainties at the unprecedented low, it is essential to investigate contributions from the higher-order systematics to achieve the ambitious goal of securing the most precise clock frequency standard. In this context, we have analysed contributions to the BBR shifts from the multipolar polarizabilities in a few ion clocks.     

Generation of cw 243 nm radiation and application to laser spectroscopy of the strontium isotopes

Intra-cavity second harmonic generation in a ring dye laser using lithium formate monohydrate has been observed to produce tunable cw UV radiation around 243 nm with single frequency powers of up to 1.4 mW. This wavelength region is of particular interest in the context of Doppler-free spectroscopy of atomic hydrogen. The radiation was used to excite an atomic beam of strontium to study the transition 5s^{2 1}S₀-4d5p ¹P₁ of Sr I. The isotope shifts were determined as follows: ⁸⁸Sr-⁸⁷Sr 123.7(8) MHz; ⁸⁸Sr 285.0(8) MHz; ⁸⁸Sr-⁸⁴Sr 600.1(9) MHz. The values are compared with results for other lines and muonic isotope shifts to obtain the specific mass shift and field shift in this transition and to study the configuration mixing effects. The hyperfine structure of ⁸⁷Sr was not resolved, the intervals being very much less than the measured linewidth of 25 MHz.     

Once upon a time,in the Soviet Union …

Radiation reaction (but, more generally, fluctuations and dissipation) occurs when a system interacts with a heat bath, a particular case being the interaction of an electron with the radiation field. We have developed a general theory for the case of a quantum particle in a general potential (but, in more detail, an oscillator potential) coupled to an arbitrary heat bath at arbitrary temperature, and in an external time-dependent c-number field. The results may be applied to a large variety of problems in physics but we concentrate by showing in detail the application to the blackbody radiation heat bath, giving an exact result for the radiation reaction problem which has no unsatisfactory features such as the runaway solutions associated with the Abraham–Lorentz theory. In addition, we show how atomic energy and free energy shifts due to temperature may be calculated. Finally, we give a brief review of applications to Josephson junctions, quantum statistical mechanics, mesoscopic physics, quantum information, noise in gravitational wave detectors, Unruh radiation and the violation of the quantum regression theorem.     

Highly selective multistep ionization of atoms by laser radiation

The possibility of dramatic selectivity increase during the stepwise ionization of atoms due to selective excitation at every step has been examined. Evaluations have been made to estimate the selectivity of excitation and ionization by laser radiation of some atoms, their isotopic shifts of absorption lines being observed at several excitation steps, for instance those of U, Yb, Gd. During three-step ionization of Yb atoms in atomic beam one may obtain an excitation selectivity equal to 4.4 × 10¹⁶ cm².     

Atomic-based stabilization for laser-pumped atomic clocks

We describe a novel technique for stabilizing frequency shifts in laser-interrogated vapor-cell atomic clocks. The method suppresses frequency shifts due to changes in the laser frequency, intensity, and modulation index as well as atomic vapor density. The clock operating parameters are monitored by using the atoms themselves, rather than by using conventional schemes for laser frequency and cell temperature control. The experiment is realized using a chip-scale atomic clock. The novel atomic-based stabilization approach results in a simpler setup and improved long-term performance.     

Creation of Molecular Vortex

The molecular vortex is predicted to be generated from an atomic Bose-Einstein condensate through the two-color photoassociation process with a specially designed field configuration in which a Gaussian and a first-order Laguerre Gaussian laser beam are applied between the bound-bound and free-bound transition, respectively. We show that such a configuration can lead to a coherent superposition of an atomic condensate and a molecular quantized vortex. We develop stimulated adiabatic passages to minimize the effect of mean-field shifts due to collisions for optimal conversi9n of an atomic condensate into a ground molecular vortex.     

Atomic beam focusing by a near-field atomic microlens

Atomic beam focusing by an atomic microlens formed by the optical field diffracted from a circular aperture in a metallic screen is considered for an aperture diameter smaller than the wavelength of the field. Analytic expressions are derived for the dipole gradient force acting on an atom in the field of diffracted radiation. It is shown that the action of the gradient force makes it possible to focus the atomic beam into a spot with a diameter on the order of a few nanometers. Numerical estimates are obtained for the focusing properties of the atomic microlens in the model describing the dipole interaction of Rb atoms with laser radiation in the vicinity of the D line.     

142—146,148,150Nd+同位素位移的共线快离子束激光光谱学实验研究

原子光谱中,同位素位移是少数几个能够将原子物理学和原子核物理学这两个不同的物理学分支联系起来的课题之一.本文利用共线快离子束激光光谱学方法,测量了正一价钕离子所有7个稳定同位素(A=142—146,148,150)之间的能量位移.与已有的结果比较,测量精度提高了一个数量级 关键词： 同位素位移 快离子束激光光谱学     

Mg 2p shallow core-level and local atomic structure of i-ZnMgRE quasicrystals

We present a detailed analysis of the Mg 2p shallow core-levels measured on icosahedral single-grain ZnMgY, ZnMgHo, and ZnMgEr quasicrystals during a photoelectron microscopy study. The synchrotron radiation photoemission measurements were performed on in situ cleaved samples at a pressure of 10⁻¹⁰ mbar and at low temperature, typically 90-150 K. The Mg 2p photoemission lines are essentially broadened as compared to those of the Mg 2p spin-orbit doublet recorded on the Zn₂Mg crystalline Laves phase. The broadening is associated to the coordination shifts of the Mg 2p level due to the inequivalent magnesium sites in the quasicrystalline lattice. The coordination shifts are calculated on the basis of i-ZnMg(Ho, Y) atomic structure data, recently determined from the pair distribution function analysis. The coordination shifts obtained are up to 0.2 eV. The Mg 2p experimental spectral intensity is nicely reproduced by a superposition of coordination-shifted Mg 2p spin-orbit doublets.     

~(142—146,148,150)Nd~ 同位素位移的共线快离子束激光光谱学实验研究

原子光谱中 ,同位素位移是少数几个能够将原子物理学和原子核物理学这两个不同的物理学分支联系起来的课题之一 .本文利用共线快离子束 激光光谱学方法 ,测量了正一价钕离子所有 7个稳定同位素 (A =142— 146 ,148,15 0 )之间的能量位移 .与已有的结果比较 ,测量精度提高了一个数量级     

Difference between a photon's momentum and an atom's recoil

When an atom absorbs a photon from a laser beam that is not an infinite plane wave, the atom's recoil is less than variant Planck's k in the propagation direction. We show that the recoils in the transverse directions produce a lensing of the atomic wave functions, which leads to a frequency shift that is not discrete but varies linearly with the field amplitude and strongly depends on the atomic state detection. The same lensing effect is also important for microwave atomic clocks. The frequency shifts are of the order of the naive recoil shift for the transverse wave vector of the photons.     

Coherent Control of the Goos-Hänchen Shifts in a Four-Level N Type Atomic Medium

The behavior of the Goos-Hänchen (GH) shifts of the reflected and transmitted probe light beams is theoretically investigated. In a fixed geometrical configuration, the effect of quantum interference induced by spontaneous emission on the phase control of the GH shifts is analyzed in this paper. It is found that in a four-level N-type atomic system as an intracavity medium, the GH shifts of the reflected and transmitted probe light beam are completely phase dependent.     

Radiative Energy Shifts of an Accelerated Multilevel Atom Coupled to the Derivative of a Scalar Field

We study the energy level shifts of an accelerated multilevel atom in dipole coupling to the derivative of a quantum massless scalar field and separately calculate the contributions of vacuum fluctuations and radiation reaction to the shifts. It is found that, in contrast to the case of a monopole-like interaction, both the vacuum fluctuations and radiation reaction contributions are changed by acceleration, and they all contain non-thermal correction terms. Our results suggest that the effect of acceleration on the energy shifts is dependent on the type of the interaction between the atom and the quantum field.     

原子电性作用矢量用于氨基酸化学位移计算

提出了用于表征分子内部化学微环境的结构描述子：原子电性作用矢量(AEIV)，并将其应用于20个天然氨基酸103个¹³C 原子核磁共振化学位移CS建模：δ =-190.514+7.352×ν₁+63.998×ν₂+49.252×ν₃+39.678×ν₄，取得优良效果. 模型值、留一法(LOO)和留分法(LMO)交互校验的复相关系数分别为R_MM=0.966 0,RLOO=0.957 7和R_LMO=0.957 7.     

Atom-solid 3p level binding energy shift of transition metals Cr,Mn, Fe,Co, and Ni

Binding energy shifts between atomic and solid phases for transition metals Cr, Mn, Fe, Co, and Ni have been obtained for 3p subshells from simultaneously recorded atomic vapor and solid state spectra. This experimental technique provides higher accuracy in comparison to separate measurements and allows direct determination of the shifts. The observed shift values are compared to values obtained using the semiempirical Born–Haber cycle method and the peak structures of the solid state photoelectron spectra are compared to atomic 3p spectra. The binding energy shift of Cr is found to be much smaller than that of the other studied elements.