Anomalous transitions in two-level systems driven by the ac Stark effect

2001 ◽  
Vol 79 (2-3) ◽  
pp. 533-545 ◽  
Author(s):  
W L Meerts ◽  
I Ozier ◽  
J T Hougen
Keyword(s):  
Molecular Beam ◽  
Stark Effect ◽  
Electric Resonance ◽  
Avoided Crossing ◽  
Different Types ◽  
Two Level Systems ◽  
Experimental Findings ◽  
Ac Stark Effect ◽  
Unusual Type ◽  
Good Agreement

An unusual type of nonresonant absorption signal produced by the ac Stark effect has been observed in a two-level avoided-crossing system. The theory for these anomalous transitions has been developed. The nonresonant signals have been shown to be caused by the perturbation by the oscillating field of the dephasing of the two-level system at the avoided crossing. A series of measurements of these anomalous transitions has been carried out using the avoided-crossing molecular-beam electric-resonance technique. In addition, different types of resonant multiphoton transitions have been investigated. Results are reported for the AE-barrier anticrossing with J = 1 in CH3SiH3. The experimental findings are in good agreement with the theory developed. PACS Nos.: 33.20Bx, 33.80Be, 42.50Hz

Avoided-crossing molecular-beam spectroscopy of symmetric tops. I. Phosphoryl fluoride (OPF3)

1981 ◽  
Vol 59 (1) ◽  
pp. 150-171 ◽  
Author(s):  
Irving Ozier ◽  
W. Leo Meert
Keyword(s):  
Dipole Moment ◽  
Molecular Beam ◽  
Wave Functions ◽  
Matrix Elements ◽  
Centrifugal Distortion ◽  
Electric Resonance ◽  
Avoided Crossing ◽  
Mixing Matrix ◽  
The Individual

A new avoided-crossing technique using a conventional molecular beam electric resonance spectrometer has been developed for studying symmetric rotors. By means of an external electric field, two levels with different values of K are made nearly degenerate and normally forbidden electric-dipole transitions between the interacting levels are observed. Mixing matrix elements ηST with ΔK = ± 3 arise from the centrifugal distortion dipole moment μD and mixing terms ηHYP, with ΔK = ± 1, ± 2 arise from the nuclear hyperfine Hamiltonian. Explicit expressions for ηHYP are given in an Appendix. Many of these terms break the symmetry of both the rotational and nuclear spin parts of the wave functions. The avoided-crossing method is discussed in detail, with emphasis on its application to the measurement of (A0–B0). It is shown how the technique can be used to determine the perpendicular moment μD, as well as μJ, and μK, the constants which characterize the dependence of the parallel dipole moment μ on J and K, respectively. Other applications include the experimental investigation of the selection rules for the individual terms in ηHYP and the determination of the sign of the rotational g-factors [Formula: see text] and [Formula: see text].∙The method has been applied to phosphoryl fluoride (OPF3). It has been determined that (A0–B0) = 217.4987(44) MHz, μD = 5.856(20) × 10−6 D, μJ = −3.38(10) × 10−6 D, and both [Formula: see text] and [Formula: see text] are negative.

Beiträge zum Stark-Effekt der Moleküle 205Tl19F und 39K19F / Contributions to the Stark-Effect of the Molecules 205Tl19F and 39K19F

1972 ◽  
Vol 27 (1) ◽  
pp. 100-110 ◽  
Author(s):  
H. Dijkerman ◽  
W. Flegel ◽  
G. Gräff ◽  
B. Mönter
Keyword(s):  
Molecular Beam ◽  
Stark Effect ◽  
Centrifugal Distortion ◽  
Vibrational States ◽  
Electric Resonance ◽  
Electrical Field ◽  
Rigid Rotator ◽  
Rotational Transitions ◽  
Vibration Rotation ◽  
Anharmonicity Of Vibration

Abstract The dominant contribution to the Stark-effect energy of polar 1Σ diatomic molecules can be calculated from the model of the rigid rotator. Additional terms arise from the anharmonicity of vibration, the centrifugal distortion, the vibration-rotation interaction and the electronic polarizability.These contributions to the Stark-effect have been investigated for the molecules 205TlF and 39KF with a molecular beam electric resonance apparatus suitable to detect rotational transitions. Measure-ments have been performed at values of electrical field corresponding a) to a minimum in the frequency for the transition (J, mJ) = (1, 0) → (2,0) for vibrational states v = 0, 1, 2 and b) cor-responding to the electrical field where the transitions (J, mJ) = (1, 0) (0, 0) and (1, 0) → (2, 0) for v = 0 occur at the same frequency.Interpretation of our data requires more precise values of the Dunham coefficients than have been published to date. These coefficients therefore have been recalculated from rotational transitions measured at zero electrical field.

The molecular beam electric resonance spectrum of OPF3

1979 ◽  
Vol 57 (8) ◽  
pp. 1163-1173 ◽  
Author(s):  
W. Leo Meerts ◽  
Irving Ozier ◽  
Antoni Dymanus
Keyword(s):  
Molecular Beam ◽  
Stark Effect ◽  
Resonance Spectrum ◽  
Rotational Temperature ◽  
Resonance Method ◽  
Partition Functions ◽  
Vibrational States ◽  
Electric Resonance ◽  
Magnetic Resonance Data ◽  
Beam Technique

The molecular-beam electric resonance spectrum of phosphoryl fluoride (16OPF3) has been investigated. A hyperfine study of (K = 0) multiplets has been combined with earlier magnetic resonance data and chemical shift arguments to obtain four spin–rotation constants and two tensor spin–spin constants. The results (in kHz) are: [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], dFF = −2.3(9), and dFF = 4.1(9). A study of molecular magnetic effects has yielded the two molecular g-factors [Formula: see text] and [Formula: see text] as well as the anisotropy in the susceptibility [Formula: see text]. The molecular quadrupole moment has been calculated. From a study of the Stark effect, the electric dipole moment has been determined for the ground vibrational state and for the (ν5 = 1) and (ν6 = 1) fundamentals. The results are: μ = 1.86847(10) D, (μ5 − μ)/μ = −3.49(4) × 10−3, and (μ6 − μ)/μ = −0.65(4) × 10−3. For each of these two excited vibrational states, the l-doubling constants qt, and DqJ(t) (t = 5,6) have been obtained. This work demonstrates that the molecular beam electric resonance method can be applied to symmetric tops with relatively large room temperature rotational partition functions by reducing the rotational temperature to a few degrees kelvin with the seeded beam technique.

Microcavities

2017 ◽  
Author(s):  
Alexey V. Kavokin ◽  
Jeremy J. Baumberg ◽  
Guillaume Malpuech ◽  
Fabrice P. Laussy
Keyword(s):  
Quantum Wells ◽  
Strong Light ◽  
Fundamental Physics ◽  
Postgraduate Students ◽  
Optical Cavities ◽  
Semiconductor Quantum Wells ◽  
Exciton Polaritons ◽  
Different Types ◽  
Potential Applications ◽  
Experimental Findings

Both rich fundamental physics of microcavities and their intriguing potential applications are addressed in this book, oriented to undergraduate and postgraduate students as well as to physicists and engineers. We describe the essential steps of development of the physics of microcavities in their chronological order. We show how different types of structures combining optical and electronic confinement have come into play and were used to realize first weak and later strong light–matter coupling regimes. We discuss photonic crystals, microspheres, pillars and other types of artificial optical cavities with embedded semiconductor quantum wells, wires and dots. We present the most striking experimental findings of the recent two decades in the optics of semiconductor quantum structures. We address the fundamental physics and applications of superposition light-matter quasiparticles: exciton-polaritons and describe the most essential phenomena of modern Polaritonics: Physics of the Liquid Light. The book is intended as a working manual for advanced or graduate students and new researchers in the field.

scholarly journals Constitutive Modeling of the Densification Behavior in Open-Porous Cellular Solids

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2731
Author(s):  
Ameya Rege
Keyword(s):  
Constitutive Model ◽  
Cell Walls ◽  
Compressive Strain ◽  
Pore Collapse ◽  
Compressive Response ◽  
Linear Elastic ◽  
Nonlinear Springs ◽  
Different Types ◽  
Point Of Intersection ◽  
Good Agreement

The macroscopic mechanical behavior of open-porous cellular materials is dictated by the geometric and material properties of their microscopic cell walls. The overall compressive response of such materials is divided into three regimes, namely, the linear elastic, plateau and densification. In this paper, a constitutive model is presented, which captures not only the linear elastic regime and the subsequent pore-collapse, but is also shown to be capable of capturing the hardening upon the densification of the network. Here, the network is considered to be made up of idealized square-shaped cells, whose cell walls undergo bending and buckling under compression. Depending on the choice of damage criterion, viz. elastic buckling or irreversible bending, the cell walls collapse. These collapsed cells are then assumed to behave as nonlinear springs, acting as a foundation to the elastic network of active open cells. To this end, the network is decomposed into an active network and a collapsed one. The compressive strain at the onset of densification is then shown to be quantified by the point of intersection of the two network stress-strain curves. A parameter sensitivity analysis is presented to demonstrate the range of different material characteristics that the model is capable of capturing. The proposed constitutive model is further validated against two different types of nanoporous materials and shows good agreement.

Immunological Determined Plasminogen Groups And Its Possible Biological Relevance

1981 ◽  
Author(s):  
V Sachs ◽  
R Dörner ◽  
E Szirmai
Keyword(s):  
Human Plasma ◽  
Type I ◽  
Type Ii ◽  
Precipitation Line ◽  
Gene Frequencies ◽  
Type Iii ◽  
Different Types ◽  
Human Plasminogen ◽  
Gel Diffusion ◽  
Good Agreement

Anti human plasminogen sera of the rabbit precipitate human plasma in the agar gel diffusion test by means of intra-basin absorption with plasminogenfree human plasma with three different types: type I is represented by one strong precipitation line, type II by two lines, a big one and a small one, and type III by three slight but distinct lines. The following frequencies of the different types have been observed in a sample of 516 human plasmas: type I 65%, type II 33% and type III 2%. Suppose the types are phenotypical groups of a diallelic system where the types I and III represent the homozygous genotypes and the type II the heterozygous the estimated gene frequencies are in good agreement with the expected values. There is also a good agreement of the distribution of plasminogen groups determined by electrofocussing from RAUM et al. and HOBART. The plasminogen groups possibly may have also a biological meaning because the plasmas of type III always have a lesser fibrinolytic activity than the plasmas of the other types.

Perturbative calculation of the ac Stark effect by the complex rotation method

1991 ◽  
Vol 43 (11) ◽  
pp. 6272-6283 ◽  
Author(s):  
Liwen Pan ◽  
K. T. Taylor ◽  
Charles W. Clark
Keyword(s):  
Stark Effect ◽  
Perturbative Calculation ◽  
Complex Rotation ◽  
Rotation Method ◽  
Ac Stark Effect

Optimization of Cold-Formed Channel Sections Using Imperialist Competitive Algorithm

2012 ◽  
Vol 166-169 ◽  
pp. 493-496
Author(s):  
Roya Kohandel ◽  
Behzad Abdi ◽  
Poi Ngian Shek ◽  
M.Md. Tahir ◽  
Ahmad Beng Hong Kueh
Keyword(s):  
Sequential Quadratic Programming ◽  
Optimization Problems ◽  
Imperialist Competitive Algorithm ◽  
Computational Method ◽  
Compression Force ◽  
Sqp Method ◽  
Competitive Algorithm ◽  
Different Types ◽  
Formed Channel ◽  
Good Agreement

The Imperialist Competitive Algorithm (ICA) is a novel computational method based on the concept of socio-political motivated strategy, which is usually used to solve different types of optimization problems. This paper presents the optimization of cold-formed channel section subjected to axial compression force utilizing the ICA method. The results are then compared to the Genetic Algorithm (GA) and Sequential Quadratic Programming (SQP) algorithm for validation purpose. The results obtained from the ICA method is in good agreement with the GA and SQP method in terms of weight but slightly different in the geometry shape.

Disorientations in dislocation structures: Formation and spatial correlation

2002 ◽  
Vol 17 (9) ◽  
pp. 2433-2441 ◽  
Author(s):  
Wolfgang Pantleon
Keyword(s):  
Plastic Deformation ◽  
Spatial Correlation ◽  
Distribution Functions ◽  
Scaling Behavior ◽  
Dislocation Dynamics ◽  
Slip Systems ◽  
Experimental Findings ◽  
Good Agreement

During plastic deformation, dislocation boundaries are formed and orientation differences across them arise. Two different causes lead to the formation of two kinds of deformation-induced boundaries: a statistical trapping of dislocations in incidental dislocation boundaries and a difference in the activation of slip systems on both sides of geometrically necessary boundaries. On the basis of these mechanisms, the occurrence of disorientations across both types of dislocation boundaries is modeled by dislocation dynamics. The resulting evolution of the disorientation angles with strain is in good agreement with experimental observations. The theoretically obtained distribution functions for the disorientation angles describe the experimental findings well and explain their scaling behavior. The model also predicts correlations between disorientations in neighboring boundaries, and evidence for their existence is presented.

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