Trapped ions provide an interesting physical scenario wherein fundamental aspects of quantum mechanics may be tested and useful applications in quantum computation may be realized [1]. Generally speaking, a time dependent quadrupolar electric field is responsible for a charged particle dynamics which may be effectively described as the motion of a point into a quadratic potential [2]. When the ...

Charge transfer between hyperthermal alkali atoms and metallic scattering surfaces is an experimental and theoretical arena for many-body interactions. To model new facets, we use a generalized time-dependent Newns-Anderson Hamiltonian that includes electron spin, multiple atomic orbitals with image shifted levels, intra-atomic Coulomb repulsion, and resonant exchange. A variational electronic ...

The relation between level crossings, entanglement, and Berry phases is investigated for the Breit-Rabi Hamiltonian of hydrogen and sodium atoms, describing a hyperfine interaction of electron and nuclear spins in a magnetic field. It is shown that the entanglement between nuclear and electron spins is maximum at avoided crossings. An entangled state encircling avoided crossings acquires a marg...

Recent advances in optical Feshbach resonance technique have enabled the experimental investigation of atomic gases with time-dependent interaction. In this work, we study many-body dynamics weakly interacting bosons subject an arbitrary time varying scattering length. By employing a variational ansatz, derive effective Hamiltonian that governs thermal particles. Crucially, show there exists hi...

We study a bipartite Kronig-Penney model with negative Dirac-delta potentials that may be used, amongst other models, to interpret plasmon propagation in nanoparticle arrays. Such system can mapped into Su-Schrieffer-Heeger-like however, general, the overlap between 'atomic' wavefunctions of neighbouring sites is not negligible. In such case, edge states finite system, which retain their topolo...

Although the only time scale one ordinarily associates with a quantum transition is its lifetime, observations of “quantum jumps” in recent years show that the actual transition time is much shorter. I define a “jump time” as the time scale such that perturbations occurring at intervals of this duration affect the decay. In terms of the “Zeno time” (related to the second moment of the Hamiltoni...

Mean-field calculations in multidimensional deformation spaces are performed and the shape coexistence isomers generated by exotic nuclear configurations toroidal superdeformed ones addressed. We use a phenomenological mean-field Hamiltonian of Woods-Saxon type with its universal parametrization involving eight parameters fixed once for all full periodic table. Original parametric correlations ...

Atomic-like defects in solids are not considered to be identical owing the imperfections of host lattice. Here, we found that even under ambient conditions, negatively charged nitrogen-vacancy (NV$^-$) centers diamond could still manifest at Hz-precision level, corresponding a 10$^{-7}$-level relative precision, while lattice strain can destroy identity by tens Hz. All parameters involved NV$^-...

The states of an atom in external electric fields become quasi-bound since the electron can ionize by tunneling through the potential barrier into the continuum. Due to the external electric field the ionization threshold of the atom is lowered from the field-free value. This process becomes important for states close to the classical ionization energy or above. These resonance states can be st...