Search results for "Stark effect"
showing 10 items of 67 documents
29SiH4 and 30SiH4: Dipole moment parameters of the dyad from Stark effect observations with laser sidebands
1990
Abstract The linear Stark effect within the ν 2 ν 4 dyad of 29SiH4 and 30SiH4 has been investigated by applying the infrared sideband technique at microwave modulation frequencies. Two vibration-induced dipole moment parameters have been measured for each isotopomer on natural abundance samples.
Spatial correlation of laser-generated electrons and holes in quantum wells
1995
The spatial correlation of hot electrons and holes generated by light in a semiconductor quantum well (QW) is studied. For hot electron-hole pairs in a polar material, this correlation is determined by the interaction with LO-phonons. We analyze the distribution F N (r, K) of electrons and holes which are created in a given light absorption process, with respect to their relative separation r and total quasimomentum ħK, after the emission of a number N of LO-phonons. The relationship between the spatial distribution of electrons and holes in these intermediate states and the cross-section of multi-phonon resonant Raman scattering (MPRRS) is established. Spatial correlation effects are stron…
Energy levels of a quantum ring in a lateral electric field
2002
Abstract The electronic states of a semiconductor quantum ring (QR) under an applied lateral electric field are theoretically investigated and compared with those of a quantum disk of the same size. The eigenstates and eigenvalues of the Hamiltonian are obtained from a direct matrix diagonalization scheme. Numerical calculations are performed for a hard-wall confinement potential and the electronic states are obtained as a function of the electric field and the ratio r2/r1, where r2 (r1) is the outer (inner) radius of the ring. The effects of decreasing symmetry and mixing on the energy levels and wave functions due to the applied electric field are also studied. The direct optical absorpti…
NaK Λ doubling and permanent electric dipoles in low-lying1Πstates: Experiment and theory
1998
The paper presents \ensuremath{\Lambda} splittings and q factors in the NaK $D{}^{1}\ensuremath{\Pi}$ state, directly measured from the electric radio-frequency-optical double resonance (RF-ODR) in laser-induced fluorescence (LIF) for a number of vibrational states $v=1--22$ with definite rotational levels J between 7 and 46. Permanent electric dipole moment values (d) have been obtained by measuring in LIF spectra the relative intensities of ``forbidden'' lines caused by dc Stark effect induced $e/f$ mixing in the ${}^{1}\ensuremath{\Pi}$ state, with their subsequent processing, which allowed us to obtain the $q/d$ ratio. A possible influence of the hyperfine structure on the RF-ODR signal…
Measurements and calculations of Stark broadening parameters for the N I multiplet (1D)3s2D–(1D)3p2Do
2014
Calculations of line broadening parameters of a doubly excited N I transition, based on atomic structure data (taken from the literature), are reported. The obtained results were used for a critical analysis of formerly published experimental data, based on spectra measured in our laboratory. These measured spectra were then again analyzed and new broadening parameters were determined and compared with results of calculations.
Ionization energy ofLi6,7determined by triple-resonance laser spectroscopy
2007
Rydberg level energies for $^{7}\mathrm{Li}$ were measured using triple-resonance laser excitation, followed by drifted field ionization. In addition to the principal $n\phantom{\rule{0.2em}{0ex}}^{2}P$ series, weak Stark mixing from residual electric fields allowed observation of $n\phantom{\rule{0.2em}{0ex}}^{2}S$ and hydrogenic Stark manifold series at higher $n$. Limit analyses for the series yield the spectroscopic ionization energy ${E}_{I}(^{7}\mathrm{Li})=43\phantom{\rule{0.2em}{0ex}}487.159\phantom{\rule{0.2em}{0ex}}40(18)\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$. The $^{6,7}\mathrm{Li}$ isotope shift (IS) was measured in selected $n\phantom{\rule{0.2em}{0ex}}^{2}…
Stark broadening of hydrogen spectral lines with fine structure effects
2004
Formalism and numerical code have been elaborated for calculation of hydrogen line profiles in conditions of plasma in which Stark broadening and fine energy splitting are comparable and it is not possible to neglect either of them. It corresponds to the range of electron densities $10^{11} < N_e ({\rm cm}^{-3}) < 10^{15}$ . Lamb shift and spontaneous emission effects have also been included. Computer simulation method was applied in the calculations. Final results have been compared with experimental and theoretical findings by other authors.
Stark-Broadening Studies of N(I) Multiplet 3p 4P o–3d 4D at 1052.630 nm
2020
Stark-broadening studies of the N(I) multiplet 3p 4P o –3d 4D are reported. Our experimental electron impact widths of spectral lines are compared with the results of our calculations: (i) according to the standard impact theory of Griem with modification, (ii) using a computer simulation method which is based on numerical N-body code (CSM). Line shape measurements were performed using a wallstabilized arc. The radiation of the plasma emitted from homogenous plasma layers was measured using a grating spectrometer equipped with a two-dimensional detector.
Preparation of coherent superposition in a three-state system by adiabatic passage
2004
We examine the topology of eigenenergy surfaces associated to a three-state system driven by two quasi-resonant fields. We deduce mechanisms that allow us to generate various coherent superposition of two states using an additional field, far off resonances. We report the numerical validations in mercury atoms as a model system, creating the coherent superpositions of two excited states and of two states coupled by a Raman process.
Laser control of the radiationless decay in pyrazine using the dynamic Stark effect
2014
The laser control of the radiationless decay between the B(3u)(nπ*) and B(2u)(ππ*) states of pyrazine using the dynamic Stark effect has been investigated. A vibronic coupling model Hamiltonian in diabatic representation, including potential energy, transition dipole, and static polarizability surfaces as a function of the four most important vibrational modes of the molecule has been parametrized using multi-reference electronic structure calculations. The interaction of the molecule with a strong non-resonant laser pulse has been analyzed in terms of dressed potential energy surfaces. Because of the large polarizability difference between the vibronically coupled B(3u)(nπ*) and B(2u)(ππ*)…