Eric Charron

Femtosecond dynamics of NaI ionization and dissociative ionization

The femtosecond dynamics of NaI two-body (NaI+hν→NaI++e−) and three-body (NaI+hν→Na++I+e−) break-up is investigated by quantum mechanical simulations. A first femtosecond laser pulse creates an excited molecular wave packet, and an additional ultrafast photoionization step monitors its subsequent time evolution. The theoretical results are compared with available experimental data. The branching ratio between these two competing fragmentation channels is extracted and an experimental scenario is proposed to control the outcome of this reactive half-collision.

COHERENT CONTROL OF PHOTODISSOCIATION IN INTENSE LASER FIELDS

The fragmentation dynamics of the hydrogen molecular ion H2+ and of its isotopic derivate HD+subjected to an intense pulsed laser radiation are studied using quantum wave packet propagations. It is shown that bichromatic optical excitations are subject to a high degree of control through the variation of the relative phase between the two fields. A phase‐locked (ω,2ω) laser pulse is used to induce asymmetry in the angular distribution of the emitted fragments. In addition, an appreciable isotope separation in the fragmentation of HD+ is predicted. The critical role of quantum molecular interferences in such phase‐controllable processes is demonstrated.

Coherent Control of Isotope Separation in HD + Photodissociation by Strong Fields

The photodissociation of the

Quantum phase gate and controlled entanglement with polar molecules

{\mathrm{HD}}^{+}

Ultrafast molecular imaging by laser-induced electron diffraction

molecular ion in intense short-pulsed linearly polarized laser fields is studied using a time-dependent wave-packet approach where molecular rotation is fully included. We show that applying a coherent superposition of the fundamental radiation with its second harmonic can lead to asymmetries in the fragment angular distributions, with significant differences between the hydrogen and deuterium distributions in the long wavelength domain where the permanent dipole is most efficient. This effect is used to induce an appreciable isotope separation.

Theoretical analysis of a realistic atom-chip quantum gate

We propose an alternative scenario for the generation of entanglement between rotational quantum states of two polar molecules. This entanglement arises from dipole-dipole interaction, and is controlled by a sequence of laser pulses simultaneously exciting both molecules. We study the efficiency of the process, and discuss possible experimental implementations with cold molecules trapped in optical lattices or in solid matrices. Finally, various entanglement detection procedures are presented, and their suitability for these two physical situations is analyzed.

Ultrafast electro-nuclear dynamics of H2 double ionization

We address the feasibility of imaging geometric and orbital structures of a polyatomic molecule on an attosecond time scale using the laser-induced electron diffraction (LIED) technique. We present numerical results for the highest molecular orbitals of the CO{sub 2} molecule excited by a near-infrared few-cycle laser pulse. The molecular geometry (bond lengths) is determined within 3% of accuracy from a diffraction pattern which also reflects the nodal properties of the initial molecular orbital. Robustness of the structure determination is discussed with respect to vibrational and rotational motions with a complete interpretation of the laser-induced mechanisms.

Laser induced electron diffraction: a tool for molecular orbital imaging

E. Charron, M. A. Cirone, A. Negretti, 3, ∗ J. Schmiedmayer, and T. Calarco 5 Laboratoire de Photophysique Moléculaire du CNRS, Bâtiment 210 Université Paris-Sud, 91405 Orsay Cedex France ECT*, Strada delle Tabarelle 286, I-38050 Villazzano, Trento, Italy, and Dipartimento di Fisica, Università di Trento, and BEC-CNR-INFM, I-38050 Povo, Italy Institut für Physik, Universität Potsdam, Am Neuen Palais 10, 14469 Potsdam, Germany Physikalisches Institut, Universität Heidelberg, 69120 Heidelberg, Germany ITAMP, Harvard Smithsonian Center for Astrophysics, and Department of Physics, Harvard University, Cambridge, MA 02138, USA (Dated: May 30, 2020)

Ultrafast Electronuclear Dynamics ofH2Double Ionization

The ultrafast electronic and nuclear dynamics of H(2) laser-induced double ionization is studied using a time-dependent wave packet approach that goes beyond the fixed nuclei approximation. The double ionization pathways are analyzed by following the evolution of the total wave function during and after the pulse. The rescattering of the first ionized electron produces a coherent superposition of excited molecular states which presents a pronounced transient H(+)H(-) character. This attosecond excitation is followed by field-induced double ionization and by the formation of short-lived autoionizing states which decay via double ionization. These two double ionization mechanisms may be identified by their signatures imprinted in the kinetic-energy distribution of the ejected protons.

Dipole-induced electromagnetic transparency.

eld polarization, the position and relative heights of the associated fringes can be related to the molecular geometrical and orbital structure, using a simple inversion algorithm which takes into account the symmetry of the initial molecular orbital from which the ionized electron is produced. We show that it is possible to extract inter-atomic distances in the molecule from an averaged photon-electron signal with an accuracy of a few percents.