Design of UV laser pulses for the preparation of matrix isolated homonuclear diatomic molecules in selective vibrational superposition states

Quantum simulations of the electron dynamics of oriented benzene and Mg-porphyrin driven by short (<10 fs) laser pulses yield electron symmetry breaking during attosecond charge migration. Nuclear motions are negligible on this time domain, i.e., the point group symmetries G = D6h and D4h of the nuclear scaffolds are conserved. At the same time, the symmetries of the one-electron densities are broken, however, to specific subgroups of G for the excited superposition states. These subgroups depend on the polarization and on the electric fields of the laser pulses. They can be determined either by inspection of the symmetry elements of the one-electron density which represents charge migration after the laser pulse, or by a new and more efficient group-theoretical approach. The results agree perfectly with each other. They suggest laser control of symmetry breaking. The choice of the target subgroup is restricted, however, by a new theorem, i.e., it must contain the symmetry group of the time-dependent electronic Hamiltonian of the oriented molecule interacting with the laser pulse(s). This theorem can also be applied to confirm or to falsify complementary suggestions of electron symmetry breaking by laser pulses.

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Coherent Ring Currents in Chiral Aromatic Molecules Induced by Linearly Polarized UV Laser Pulses

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.543.381 ◽

2013 ◽

Vol 543 ◽

pp. 381-384 ◽

Cited By ~ 2

Author(s):

Manabu Kanno ◽

Hirohiko Koho ◽

Hirobumi Mineo ◽

Sheng Hsien Lin ◽

Yuichi Fujimura

Keyword(s):

Aromatic Ring ◽

Quantum Dynamics ◽

Ring Current ◽

Molecular System ◽

Laser Pulses ◽

Uv Laser ◽

Aromatic Molecules ◽

Ring Currents ◽

Linearly Polarized ◽

Coherent Ring

In recent years, laser control of electrons in molecular system and condensed matter has attracted considerable attention with rapid progress in laser science and technology [. In particular, control of π-electron rotation in photo-induced chiral aromatic molecules has potential utility to the next-generation ultrafast switching devices. In this paper, we present a fundamental principle of generation of ultrafast coherent ring currents and the control in photo-induced aromatic molecules. This is based on quantum dynamics simulations of π-electron rotations and preparation of unidirectional angular momentum by ultrashort UV laser pulses properly designed. For this purpose, we adopt 2,5-dichloro [(3,6) pyrazinophane (DCPH) fixed on a surface, which is a real chiral aromatic molecule with plane chirality. Here π electrons can be rotated along the aromatic ring clockwise or counterclockwise by irradiation of a linearly polarized laser pulse with the properly designed photon polarization direction and the coherent ring current with the definite direction along the aromatic ring is prepared. This is contrast to ordinary ring current in an achiral aromatic ring molecule with degenerate electronic excited state, which is prepared by a circularly polarized laser [2]. In this case, π electrons rotate along the Z-axis of the laboratory coordinates, while for the present case electrons rotate along the z-axis in molecular Cartesian coordinates. It should be noted that signals originated from the coherent ring currents prepared by linearly polarized ultrashort UV lasers are specific to the chiral molecule of interest.

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Charge Exchange between Homonuclear Diatomic Molecules and Protons

The Journal of Chemical Physics ◽

10.1063/1.1727757 ◽

1966 ◽

Vol 45 (4) ◽

pp. 1333-1338 ◽

Cited By ~ 3

Author(s):

R. G. Breene

Keyword(s):

Charge Exchange ◽

Diatomic Molecules ◽

Homonuclear Diatomic Molecules

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CVD nanodiamond thin films as high yield photocathodes driven by UV laser pulses

2014 27th International Vacuum Nanoelectronics Conference (IVNC) ◽

10.1109/ivnc.2014.6894736 ◽

2014 ◽

Author(s):

Jean-Paul Mazellier ◽

Cyril Di Giola ◽

Pierre Legagneux ◽

Clement Hebert ◽

Emmanuel Scorsonne ◽

...

Keyword(s):

Thin Films ◽

Laser Pulses ◽

High Yield ◽

Uv Laser

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Excimer Laser Interaction with Metals

MRS Proceedings ◽

10.1557/proc-285-145 ◽

1992 ◽

Vol 285 ◽

Cited By ~ 3

Author(s):

W.W. Duley ◽

G. Kinsman

Keyword(s):

Experimental Data ◽

Laser Radiation ◽

Excimer Laser ◽

Metal Surfaces ◽

Laser Pulses ◽

Radiative Properties ◽

Uv Laser ◽

Laser Interaction ◽

Excimer Laser Radiation

ABSTRACTExcimer laser radiation may be used to process metal surfaces in a variety of novel ways. The simplest of these involves the use of UV laser pulses for ablation. Ablation occurs as the result of both vaporization and hydrodynamical effects. Experimental data related to these processes will be discussed. In addition, it will be shown how specific irradiation regimes can yield metal surfaces with unique radiative properties.

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