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Filgueiras, Cleverson

Publications and source records attributed to Filgueiras, Cleverson.

Quantum motion of a point particle in the presence of the Aharonov–Bohm potential in curved space

The nonrelativistic quantum dynamics of a spinless charged particle in the presence of the Aharonov–Bohm potential in curved space is considered. We chose the surface as being a cone defined by a line element in polar coordinates. The geometry of this line element establishes that the motion of the particle can occur on the surface of a cone or an anti-cone. As a consequence of the nontrivial topology of the cone and also because of two-dimensional confinement, the geometric potential should be taken into account. At first, we establish the conditions for the particle describing a circular path in such a context. Because of the presence of the geometric potential, which contains a singular term, we use the self-adjoint extension method in order to describe the dynamics in all space including the singularity. Expressions are obtained for the bound state energies and wave functions. -- Highlights: •Motion of particle under the influence of magnetic field in curved space. •Bound state for Aharonov–Bohm problem. •Particle describing a circular path. •Determination of the self-adjoint extension parameter.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Yet another position-dependent mass quantum model

The quantum dynamics of particles with mass dependent on the position is a problem of interest since the effective-mass approach to charge carriers in conductors and semiconductors began to be used. These problems have been solved using the Hamiltonian H=(1/2)m{sup {alpha}}(x)pm{sup {beta}}(x)pm{sup {alpha}}(x), where {alpha} and {beta} are real parameters which satisfy the condition 2{alpha}+{beta}=-1. It has been verified that the choice {alpha}= 0, {beta}=-1 is compatible with Galilean invariance. In this work we propose a new Hamiltonian, H-caret=(1/6)m-caret(x-caret){sup -1}p-caret{sup 2}+p-caretm-caret(x-caret){sup -1}p-caret+p{sup 2} m-caret(x-caret){sup -1}, to describe variable mass systems. We considered every permutation among the operators, taking into account that the mass is now an operator. We verified that this Hamiltonian is Hermitian and is compatible with Galilean invariance. For comparison, we used both Hamiltonians to calculate the band structure for a quantum particle with mass varying periodically. Although qualitatively equivalent, the results turn out to produce different numerical values.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗