Rotational Heisenberg Inequalities

Since their discovery in 1927, the Heisenberg Inequalities have become an icon of quantum mechanics. Often inappropriately referred to as the Uncertainty Principle, these inequalities relating the standard deviations of the position and momentum observables to Planck's constant are one of the cornerstones of the quantum formalism even if the physical interpretation of quantum mechanics remains still open to controversy nowadays. The Heisenberg Inequalities governing translational motion are well understood. However, the corresponding inequalities pertaining to rotational motion have not been established so far. To fill this gap, we present here the Rotational Heisenberg Inequalities relating the standard deviations of the orientation axis and orbital angular momentum observables of an isolated molecule. The reason for choosing this system is that a molecule separated from its environment corresponds to a bound system preserving the orbital angular momentum.Comment: 6 pages, 2 figures. arXiv admin note: substantial text overlap with arXiv:1412.211

Quantum description of a rotating and vibrating molecule

A rigorous quantum description of molecular dynamics with a particular emphasis on internal observables is developed accounting explicitly for kinetic couplings between nuclei and electrons. Rotational modes are treated in a genuinely quantum framework by defining a molecular orientation operator. Canonical rotational commutation relations are established explicitly. Moreover, physical constraints are imposed on the observables in order to define the state of a molecular system located in the neighborhood of the ground state defined by the equilibrium condition.Comment: 28 page

Magnetoelectric effect in a hydrogen molecule

The symmetry breaking due to a magnetic field applied on a hydrogen molecule H2 generates an electric polarization. This magnetoelectric effect occurs for electrons in a triplet state provided the magnetic induction field is not aligned with the symmetry axis of the molecule

Quantum molecular master equations

We present the quantum master equations for midsize molecules in the presence of an external magnetic field. The Hamiltonian describing the dynamics of a molecule accounts for the molecular deformation and orientation properties, as well as for the electronic properties. In order to establish the master equations governing the relaxation of free-standing molecules, we have to split the molecule into two weakly interacting parts, a bath and a bathed system. The adequate choice of these systems depends on the specific physical system under consideration. Here we consider a first system consisting of the molecular deformation and orientation properties and the electronic spin properties and a second system composed of the remaining electronic spatial properties. If the characteristic time scale associated with the second system is small with respect to that of the first, the second may be considered as a bath for the first. Assuming that both systems are weakly coupled and initially weakly correlated, we obtain the corresponding master equations. They describe notably the relaxation of magnetic properties of midsize molecules, where the change of the statistical properties of the electronic orbitals is expected to be slow with respect to the evolution time scale of the bathed system

Quantum description of a rotating and vibrating molecule

A rigorous quantum description of molecular dynamics with a particular emphasis on internal observables is developed accounting explicitly for kinetic couplings between nuclei and electrons. Rotational modes are treated in a genuinely quantum framework by defining a molecular orientation operator. Canonical rotational commutation relations are established explicitly. Moreover, physical constraints are imposed on the observables in order to define the state of a molecular system located in the neighborhood of the ground state defined by the equilibrium condition. Graphical abstract

Job requirements for control room jobs in nuclear power plants

Together with other variables, human factors play a central role in the safety of highly complex technical systems such as nuclear power plants. However, despite the unquestionable importance of human factors, little information is available about relevant ability requirements for control room jobs in nuclear power plants. The purpose of this study was to close this gap, to provide specific information about ability requirements for such jobs, and to evaluate how several hypothesized factors (ability domain, type of job, and operating condition) contribute to ability requirements. We found that high levels of cognitive as well as social/interpersonal abilities are needed for control room jobs, and that ability requirements increase with the hierarchical job level for these two domains but decrease for psychomotor/physical abilities and for sensory/perceptual abilities. Furthermore, specifically concerning jobs with a leadership function, we found some differences between incidents and normal operations regarding requirements for social/interpersonal abilities, indicating that the former require a different leadership style than the latter