Search results for "quant-ph"

Symmetry-adapted tensorial formalism to model rovibrational and rovibronic spectra of molecules pertaining to various point groups

2004

International audience; We present a short review on the tensorial formalism developed by the Dijon group to solve molecular spectroscopy problems. This approach, originally devoted to the rovibrational spectroscopy of highly symmetrical species (spherical tops) has been recently extended in several directions: quasi-spherical tops, some symmetric and asymmetric tops, and rovibronic spectroscopy of spherical tops in a degenerate electronic state. Despite its apparent complexity (heavy notations, quite complex mathematical tools), these group theoretical tensorial methods have a great advantage of flexibility: a systematic expansion of effective terms for any rovib- rational/rovibronic probl…

Implementation of single-qubit quantum gates by adiabatic passage and static laser phases

2006

International audience; We propose and analyse experimentally feasible implementations of single-qubit quantum gates based on stimulated Raman adiabatic passage (STIRAP) between magnetic sublevels in atoms coupled by elliptically polarized pulsed laser fields, in part based on a proposal by Kis and Renzoni [Z. Kis, F. Renzoni, Phys. Rev. A 65 (2002) 032318]. These techniques require only the control of the relative phase of the driving fields but do not involve any dynamical or geometric phases, which makes it independent of the other interaction details: detuning, pulse shapes, pulse areas and pulse durations. The suggested techniques are immune to spontaneous emission since the qubit mani…

Ultrafast stimulated Raman parallel adiabatic passage by shaped pulses

2009

We present a general and versatile technique of population transfer based on {\it parallel adiabatic passage} by femtosecond shaped pulses. Their amplitude and phase are specifically designed to optimize the adiabatic passage corresponding to parallel eigenvalues at all times. We show that this technique allows the robust adiabatic population transfer in a Raman system with the total pulse area as low as 3 $\pi$, corresponding to a fluence of one order of magnitude below the conventional stimulated Raman adiabatic passage process. This process of short duration, typically pico- and subpicosecond, is easily implementable with the modern pulse shaper technology and opens the possibility of ul…

On the Study of the Very High Excited Vibrational Levels of the Pyramidal Molecules

2006

Algebraic Approach to Vibrational Spectra of Stibine Molecule

2002

International audience

U(p+1) : Application aux états moléculaires très excités.

2004

International audience

Algebraic Hamiltonian Adapted to Strech-Bend Coupling in the Stibine Molecule.

2003

Application du formalisme U(p+1) à la molécule de silane

1997

Séminaire invité, Université de Villeneuve d'Ascq, France

Symmetrized rovibrational local states for triply degenerate modes of spherical molecules: application to intensity calculations in the nu3 ladder

1998

International audience; XY6 octahedral molecules, like SF6, WF6 and UF6, reveal a localized behaviour in the excited states of their stretching mode nu3. This character may be described through the G U (3) K3 O_h group chain (Boujut, V., Michelot, F., and Leroy, C., 1998, Molec. Phys., 93, 879). In this paper, we extend our previous theoretical developments by: the construction of a symmetrized local rovibrational basis, denoted |n;J_eta|K|Gamma mu>, well adapted to the study of the(n 00) states of the nu3 ladder the introduction of an approximate infrared intensity model for the transitions (000) (n 00) with n odd. We believe that the simplicity of the analytic expressions obtained in each…

The U(p+1) formalism applied to XY3 molecules in vibrationaly high excited states

2005

Séminaire invité : Institut for Physical Research, NASA ; Ashtarak, Arménie