Search results for "homonuclear molecule"
showing 9 items of 19 documents
Even harmonics from laser driven homonuclear molecules
2007
The dynamics of a homonuclear diatomic molecule driven by a laser pulse is obtained beyond the fixed nuclei approximation. Laser parameters can be adjusted to confine the electron over one of the two nuclei for a relatively long time or not. A time-resolved analysis of the electromagnetic spectrum emitted by the molecule presents the usual odd harmonics far from confinement and even harmonics during the confinement periods. A physical interpretation of the results is given.
Control of Electron Motion in a Molecular Ion: Dynamical Creation of a Permanent Electric Dipole
2007
The dynamics of a diatomic one-dimensional homonuclear molecule driven by a two-laser field is investigated beyond the usual fixed nuclei approximation. The dynamics of the nuclei is treated by means of Newton equations of motion; the full quantum description is used for the single active electron. The first laser pulse (pump) excites vibrations of the nuclei, while the second very short pulse (probe) has the role of confining the electron around one of the nuclei. We show how to use the radiation scattered in these conditions by the molecule to achieve real-time control of the molecular dynamics.
The dynamics of the electron in a homonuclear driven molecular ion
2004
Abstract The radiation diffused by a one-dimensional homonuclear molecular ion driven by a laser field is studied as a function of the time. When the photon energy is resonant with the energy gap between the ground and the first excited state, the electronic probability density is seen to undergo slow and deep oscillations between the two nuclei. Synchronous to such oscillations, deep modulations of the emitted power are observed. The period of oscillation is of the order of 10 optical cycles. Detection of the variation in the intensity of the emitted electromagnetic spectrum therefore brings information on the position of the electron in the molecule.
Polarization of high harmonic generated spectra in H+2ion
2013
AbstractWe study the polarization of the harmonics generated by a homonuclear diatomic molecule in the presence of an intense, linearly polarized laser field. The polarization parameters of the emitted radiation are investigated as a function of the angle between the laser electric field and the molecular axis. The calculations are carried out by assuming a single active electron model with fixed nuclei; a two-dimensional model of the system is used. We find a different dependence of the parameters of the harmonics vs in the first or second half of the emitted spectrum. In particular, the differences are accentuated for , while for higher angles, until the perpendicular orientation, almost …
Purely long-range polar molecules composed of identical lanthanide atoms
2019
International audience; Doubly polar molecules, possessing an electric dipole moment and a magnetic dipole moment, can strongly couple to both an external electric field and a magnetic field, providing unique opportunities to exert full control of the system quantum state at ultracold temperatures. We propose a method for creating a purely long-range doubly polar homonuclear molecule from a pair of strongly magnetic lanthanide atoms, one atom being in its ground level and the other in a superposition of quasi-degenerate opposite-parity excited levels [Phys. Rev. Lett. 121, 063201 (2018)]. The electric dipole moment is induced by coupling the excited levels with an external electric field. W…
Control of the high harmonic generation spectra by changing the molecule-laser field relative orientation
2010
The time dependent Schrodinger equation of a homonuclear diatomic molecule in the presence of a linearly polarized laser field is numerically solved by means of a split-operator parallel code. The calculations are carried out by assuming a single active electron model with fixed nuclei; a simplified two-dimensional model of the system is used. The highly nonlinear response of the electron wave function to the laser electric field stimulates the molecule to emit electromagnetic radiation consisting of a wide plateau of odd harmonics of the laser field. It is shown that the emitted spectrum can be finely controlled by changing the angle between the laser electric field and the molecular axis;…
Application of 29Si Homonuclear and 1H−29Si Heteronuclear NMR Correlation to Structural Studies of Calcium Silicate Hydrates
2004
Structural characterization of calcium silicate hydrate (C-S-H) is of major importance, as it is the main constituent of Portland cement and is responsible for its principal cohesion and durability...
Conformation and concerted dynamics of the integrin-binding site and the C-terminal region of echistatin revealed by homonuclear NMR
2005
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Spectrum emitted by a trapped electron
2007
We study the behaviour of a homonuclear molecule driven by an intense laser field. Newton's laws are used to describe the dynamics of nuclei while the quantal approach is reserved to the study of the electron. It is observed that the nuclei can oscillate or dissociate according to the degree of ionization of the molecule. In case of low ionization rate it is shown that great amount of information can be obtained by using the simplified approaches of fixed nuclei and of two-state approximation. Under suitable conditions the electron wave function spends a long time localized around one nucleus. The harmonic generation of the molecule is studied and seen to contain even harmonics.