Rocío Jáuregui

Symmetry-eigenfunctions for many-electron atoms and molecules: A unified and friendly approach for frontier research and student training

Abstract Atomic and molecular many-electron symmetry-eigenfunctions are obtained by means of a FORTRAN program based on projection operators and ordered Slater determinants. When degeneracies exist, Schmidt orthonormalization of a conveniently ordered manifold allows for the construction of a hierarchy of interacting spaces, unattainable through Racah algebra or group-theoretical methods, but necessary for compact many-electron theories and calculations beyond Hartree-Fock. Through a strict modular organization, this program offers a variety of concurrent evolution pathways covering all kinds of symmetry-eigenfunctions. Also, the results it generates can be fed into other modules for the general and efficient calculation of many-electron wave functions, or for symbolic evaluation of selected many-electron matrix elements of symmetry-operators such as the Hamiltonian. The program may be run interactively or in batch form to produce lists of configuration state functions for actual electronic structure calculations. In tutorial and interactive modes, help, status and overview commands can be invoked as an aid to gain working knowledge on many-electron symmetry-eigenfunctions. Standard FORTRAN 77 and full validation of array dimensions expressed in terms of parameters ensure widespread portability.

All-optical 3D atomic loops generated with Bessel light fields

The propagation invariance of Bessel beams as well as their transversal structure are used to perform a comparative analysis of their effect on cold atoms for four different configurations and combinations thereof. We show that, even at temperatures for which the classical description of the atom center of mass motion is valid, the interchange of momentum, energy and orbital angular momentum between light and atoms yields efficient tools for all-optical trapping, transporting and, in general, manipulating the state of motion of cold atoms.

Spin eigenfunctions for many-electron calculations

Abstract We discuss a modular and efficient FORTRAN program which operating on a given linear combination of Slater determinants generates a spin eigenfunction by means of a symmetric, idempotent and hermtitian projection operator. In combination with other modules described in two previous and three further papers it may be used to generate all symmetry eigenfunctions needed in atomic and molecular electronic structure calculations. In particular, first-order and second-order interacting spaces are discussed.

Angular momentum eigenfunctions for many-electron calculations

Abstract We discuss a modular and efficient FORTRAN program to generate many-particle jj-JM and L 2 eigenfunctions obtained as projections of a single ordered Slater determinant built up from symmetry-adapted one-electron functions. Interacting spaces useful in calculations beyond Hartree-Fock are considered. In combination with other modules described in the previous and in four further papers this program can be used to generate all symmetry-eigenfunctions needed in atomic electronic structure calculations.

A relativistic study of Bessel beams

We present a fully relativistic analysis of Bessel beams revealing some noteworthy features that are not explicit in the standard description. It is shown that there is a reference frame in which the field takes a particularly simple form, the wave appearing to rotate in circles. The concepts of polarization and angular momentum for Bessel beams are also reanalysed.

Systematic search of excited states of negative ions lying above the ground state of the neutral atom

Abstract Nonrelativistic fixed-core valence-shell configuration interaction calculations are carried out for excited states of atomic negative ions in the range H through Ca, in an effort to identify the ones which are metastable against autoionization. Approximate relativistic corrections are included in some cases. From Be onwards, all (Core)n(n+1)sq(n+1)pr neutrals appear to bind an extra electron into a bound ( Core ) n (n+1) s q (n+1) p r+1 2S+1 L negative ion, in all cases where the 2S+1L continuum starts at the corresponding neutral atom state. Similarly as in the recently discussed case of Li−, alkali-earths (Be−, Mg−, Ca−), Zn−, B−, Al−, C−, Si−, Ar−, and possibly S−, have two bound excited states connected by an E1 transition in regions extending from infrared to vacuum ultraviolet. Negative neon is found to decay by E1 radiation into a continuum, thus Ne− beams are unlikely to be made in the future. However, there exists a metastable [Ne]3p54s4p 4S state of negative argon, making possible the production of Ar− beams.

Dynamical constants for electromagnetic fields with elliptic-cylindrical symmetry

Taking into account the characteristics of a free scalar field in elliptic coordinates, a new dynamical variable is found for the free electromagnetic field. The conservation law associated to this variable cannot be obtained by direct application of standard Noether theorem since the symmetry generator is of second order. Consequences on the expected mechanical behavior of an atomic system interacting with electromagnetic waves exhibiting such a symmetry are also discussed.

Molecular symmetry eigenfunctions for many-electron calculations

Abstract We discuss a modular FORTRAN program which operating on an ordered Slater determinant generates an eigenfunction spanning an irreducible representation of a given molecular symmetry group. The program is supported by a database of point group representation matrices. In combination with other modules described in two previous and two further papers it may be used to acquire a working knowledge about molecular symmetry eigenfunctions and to generate lists of many-electron symmetry-adapted configurations suitable for electronic structure calculations beyond Hartree-Fock.

Comment on “Fermionic entanglement ambiguity in noninertial frames”

In this comment we show that the ambiguity of entropic quantities calculated in Physical Review A 83, 062323 (2011) for fermionic fields in the context of Unruh effect is not related to the properties of anticommuting fields, as claimed in Physical Review A 83, 062323 (2011), but rather to wrong mathematical manipulations with them and not taking into account a fundamental superselection rule of quantum field theory.

Dynamical constants of structured photons with parabolic-cylindrical symmetry

Electromagnetic modes with parabolic-cylindrical symmetry and their dynamical variables are studied both in the classical and quantum realm. As a result, a new dynamical constant for the electromagnetic field is identified and linked to the symmetry operator which supports it.