Dmitry V. Zhdanov

Wigner phase-space distribution as a wave function

We demonstrate that the Wigner function of a pure quantum state is a wave function in a specially tuned Dirac bra-ket formalism and argue that the Wigner function is in fact a probability amplitude for the quantum particle to be at a certain point of the classical phase space. Additionally, we establish that in the classical limit, the Wigner function transforms into a classical Koopman-von Neumann wave function rather than into a classical probability distribution. Since probability amplitude need not be positive, our findings provide an alternative outlook on the Wigner functions negativity.

Absolute asymmetric synthesis from an isotropic racemic mixture of chiral molecules with the help of their laser orientation-dependent selection

We analyzed the absolute asymmetric synthesis (AAS) of enantiomers from an isotropic racemic mixture of chiral molecules, which employs the laser electrodipole interaction, and revealed a set of basic symmetry-based conditions on the parameters of field-molecule interaction. Using these conditions, we developed a novel scenario of the AAS (through selective photodestruction of the enantiomers of a given type) based on the joint action of the strong multicomponent femtosecond and picosecond laser pulses. Key mechanism of this scenario is the partly modified scheme of laser orientation-dependent selection of molecules proposed by us earlier [D. V. Zhdanov et al., JETP 130, 387 (2006)]. Calculations made on example of chiral molecule SiHNaClF show rather high efficiency and stability of the proposed AAS scenario with respect to the parameters of the incident laser pulses and even feasibility of its realization at room temperature.

Coherent control of chirality in ensemble of randomly oriented molecules using a sequence of short laser pulses

The universal algorithm of choosing the train of short laser pulses, which could selectively excite the specific enantiomers in a racemic mixture of rotationally cold molecules, is proposed. Its application is illustrated on example of laser control of content of different chiral conformations in the mixture of hydrogen peroxide molecules. Methods of detection of racemity breaking in case of dynamical chirality are also discussed.

Laser-assisted molecular orientation in gaseous media: new possibilities and applications

It was shown recently by us that an isotropic distribution of molecules in gaseous media can be drastically effected via their orientation- dependent selective excitation by a strong femtosecond multicomponent laser pulse. In the present paper, we analyze the specific effects accompanying the dynamical orientation of molecules driven this way. It is demonstrated that the peculiarities of the post-pulse transient angular distribution of molecules allow original proposals for the generation of pulsed terahertz radiation and also for the determination of the molecular rotational constants.

Selective photodestruction of chiral molecules of a specified configuration by coherent laser radiation

The method of selective destruction of small chiral molecules of a specified configuration, which is based on coherent action of the intense multicomponent ps and fs laser pulses, is suggested. Computer simulation results show its efficiency for the laser distillation of a racemic mixture of randomly oriented molecules in a gas phase at room temperature.

Orientational Selection of Molecules in Combined Laser and Electrostatic Fields

It is shown that the combined effects of electrostatic and resonant laser fields on a molecular ensemble can be used to control the orientation of molecules by changing their internal state. In contrast to most other schemes for controlling molecular orientation, the proposed method does not require rotational cooling and can be highly efficient at room temperature.