Search results for "Orbit"

Angular Momentum Coupling

2007

In nuclear physics, as also in atomic and molecular physics, the entities to be described consist of sub-entities with some orbital angular momentum and spin. The angular momentum of the entity is built, then, of the angular momenta of the sub-entities. This building process leads to quantum-mechanical angular momentum coupling. This chapter presents the basic machinery for treating angular momentum and its coupling. Clebsch-Gordan coefficients and 3j symbols are introduced. It is shown that Clebsch-Gordan coefficients and 3j symbols relate to the coupling of two angular momenta. Increasing the number of angular momenta to be coupled leads to more complicated coupling patterns. Transformati…

Symmetry-induced forces on phase singularities

2010

We show the existence of external forces acting on phase singularities whose origin can be attributed to the presence of short-term discrete-symmetry potentials. These special forces can break highly charged phase singularities into single-charged ones and provide them with non-zero orbital angular momentum even when the potential no longer acts.

Distilling angular momentum nonclassical states in trapped ions

2004

In the spirit of Quantum Non-Demolition Measurements, we show that exploiting suitable vibronic couplings and repeatedly measuring the atomic population of a confined ion, it is possible to distill center of mass vibrational states with well defined square of angular momentum or, alternatively, angular momentum projection Schr\"odinger cat states.

Electric-Field-Induced Symmetry Breaking of Angular Momentum Distribution in Atoms

2006

We report the experimental observation of alignment to orientation conversion in the 7D_3/2 and 9D_3/2 states of Cs in the presence of an external dc electric field, and without the influence of magnetic fields or atomic collisions. Initial alignment of angular momentum states was created by two-step excitation with linearly polarized laser radiation. The appearance of transverse orientation of angular momentum was confirmed by the observation of circularly polarized light. We present experimentally measured signals and compare them with the results of a detailed theoretical model based on the optical Bloch equations.

Transfer of optical orbital angular momentum to a bound electron

2016

Photons can carry angular momentum, not only due to their spin, but also due to their spatial structure. This extra twist has been used, for example, to drive circular motion of microscopic particles in optical tweezers as well as to create vortices in quantum gases. Here we excite an atomic transition with a vortex laser beam and demonstrate the transfer of optical orbital angular momentum to the valence electron of a single trapped ion. We observe strongly modified selection rules showing that an atom can absorb two quanta of angular momentum from a single photon: one from the spin and another from the spatial structure of the beam. Furthermore, we show that parasitic ac-Stark shifts from…

Occupation Number Representation

2007

The first two chapters of this book presented angular momentum algebra as the basic tool of nuclear theory. That includes angular momentum coupling coefficients, spherical tensor operators and reduced matrix elements. In the preceding chapter we introduced the mean-field concept, along with associated many-nucleon wave functions, Slater determinants, describing configurations of non-interacting particles in mean-field single-particle orbitals.

Angular momentum and transition dipole moment

1995

Electric-field-induced symmetry breaking of angular momentum distribution in atoms

2007

We report the observation of alignment to orientation conversion in the 7,9 D3/2states of Cs in the presence of an electric field without the influence of magnetic fields or collisions. Initial alignment of angular momentum was created by two-step excitation with linearly polarized light. The appearance of transverse orientation was confirmed by the observation of circularly polarized fluorescence. We present measured signals and compare them with the results of a theoretical model based on the optical Bloch equations. The effect is odd under time reversal and should be taken into account in searches for an electron electric dipole moment.

Collision orbits in the oblate planet problem

1984

Some of the properties of the oblate planet problem are derived. We use the technique of blowing up the singularity to study the collision orbits. We define some families of them in terms of their asymptotic behavior.

Comb-like Turing patterns embedded in Hopf oscillations: Spatially localized states outside the 2:1 frequency locked region

2017

A generic distinct mechanism for the emergence of spatially localized states embedded in an oscillatory background is demonstrated by using 2:1 frequency locking oscillatory system. The localization is of Turing type and appears in two space dimensions as a comb-like state in either $\pi$ phase shifted Hopf oscillations or inside a spiral core. Specifically, the localized states appear in absence of the well known flip-flop dynamics (associated with collapsed homoclinic snaking) that is known to arise in the vicinity of Hopf-Turing bifurcation in one space dimension. Derivation and analysis of three Hopf-Turing amplitude equations in two space dimensions reveals a local dynamics pinning mec…