Aharonov-Bohm effect as a diffusion phenomenon

This paper presents a hydrodynamical view of the Aharonov-Bohm effect, using Nelson's formulation of quantum mechanics. Our aim is to compare our results with other systems and gain a better understanding of the mysteries behind this effect, such as why the motion of a particle is affected in a region where there is no magnetic field. Some theories suggest that this effect is due to the non-local action of the magnetic field on the particle, or even the physical significance of vector potentials over magnetic fields. Our main purpose is to use Nelson's formulation to describe the effect and demonstrate that it can be explained by the direct action of the current surrounding the magnetic field region (i.e. a cylinder) on the particle outside of it. In this context, magnetic fields and vector potentials serve as tools for finding other fundamental quantities that arise from the interaction between two fields: the quantum background fields described by Nelson's quantum theory. Finally, we investigate the relationship between hidden variables and quantum fluctuations and their role in this phenomenon.Comment: 34 pages, no figure

Entanglement in a Two-Qubit Ising Model Under a Site-Dependent External Magnetic Field

We investigate the ground state and the thermal entanglement in the two-qubit Ising model interacting with a site-dependent magnetic field. The degree of entanglement is measured by calculating the concurrence. For zero temperature and for certain direction of the applied magnetic field, the quantum phase transition observed under a uniform external magnetic field disappears once a very small non-uniformity is introduced. Furthermore, we have shown analytically and confirmed numerically that once the direction of one of the magnetic field is along the Ising axis then no entangled states can be produced, independently of the degree of non-uniformity of the magnetic fields on each site.Comment: 6 pages, 6 figure

Preparation, crystal structure and spectroscopic characterization of [Ga(OH)(SO4)(terpy)(H2O)]center dot H2O (terpy=2,2 ‘: 6 ‘,2-terpyridine): The first characterized gallium(III) sulfato complex

The reaction of Ga-2(SO4)(3).18H(2)O and excess 2,2’:6’,2”-terpyridine (terpy) in MeOH / H2O leads to [Ga(OH)(SO4)(terpy)(H2O)].H2O (1.H2O] in good yield. The structure of the complex has been determined by single-crystal X-ray crystallography. The Ga-III atom in 1.H2O is 6-coordinate and ligation is provided by one terdentate terpy molecule, one monodentate sulfate, one terminal hydroxide and one terminal H2O molecule; the coodination polyhedron about the metal is described as a distorted octahedron. There is an extensive hydrogen-bonding network in the crystal structure which generates corrugated layers parallel to bc. The new complex was characterized by IR and H-1 NMR spectroscopy. The spectroscopic data are discussed in terms of the nature of bonding