arXiv subjects

Claudio Furtado

Publications and source records attributed to Claudio Furtado.

34 records · Page 2Linked to original sources

arXiv2009

Relativistic Einstein-Podolsky-Rosen Correlations in curved spacetime via Fermi-Walker Transport

We present a geometric description to study the relativistic EPR correlations in curved spacetime background given by the application of the Fermi-Walker transport in the relativistic EPR states and we show that its result has the same effect as the applications of successive infinitesimal Lorentz boosts in the relativistic EPR states. We also show that the expression for the Bell inequality due to the Fermi-Walker transport is equivalent to the expression demonstrated by Terashima and Ueda \cite{TU2}, where the degree of violation of the Bell inequality is dependent of the angle of the Wigner rotation. This geometrical approach to study the relativistic EPR correlations is a promissing formulation to investigate the EPR correlations in the general relativity background.

quant-ph↗

arXiv2008

Gravitational Geometric Phase in the Presence of Torsion

We investigate the relativistic and non-relativistic quantum dynamics of a neutral spin-1/2 particle submitted an external electromagnetic field in the presence of a cosmic dislocation. We analyze the explicit contribution of the torsion in the geometric phase acquired in the dynamic of this neutral spinorial particle. We discuss the influence of the torsion in the relativistic geometric phase. Using the Foldy-Wouthuysen approximation, the non-relativistic quantum dynamics are studied and the influence of the torsion in the Aharonov-Casher and He-McKellar-Wilkens effects are discussed.

hep-th↗

arXiv2007

Holonomy Transformation in the FRW Metric

In this work we investigate loop variables in Friedman-Robertson-Walker spacetime. We analyze the parallel transport of vectors and spinors in several paths in this spacetime in order to classify its global properties. The band holonomy invariance is analysed in this background.

gr-qc↗

arXiv2006

Geometric Phases in Graphitic Cones

In this article we use a geometric approach to study geometric phases in graphitic cones. The spinor that describes the low energy states near the Fermi energy acquires a phase when transported around the apex of the cone, as found by a holonomy transformation. This topological result can be viewed as an analogue of the Aharonov-Bohm effect. The topological analysis is extended to a system with $n$ cones, whose resulting configuration is described by an effective defect.

cond-mat.mtrl-sci↗

arXiv2006

Aharonov-Bohm Effect and Disclinations in an Elastic Medium

In this work we investigate quasiparticles in the background of defects in solids using the geometric theory of defects. We use the parallel transport matrix to study the Aharonov-Bohm effect in this background. For quasiparticles moving in this effective medium we demonstrate an effect similar to the gravitational Aharonov- Bohm effect. We analyze this effect in an elastic medium with one and $N$ defects.

cond-mat.soft↗

arXiv2005

Landau Levels Analog to Electric Dipole

In this letter we study the quantum dyamics of a neutral particle in the presence of an external magnetic field. We demonstrate in a specific field-dipole configuration that we have a quantization similar to the Landau Levels. We investigate this quantization motivated by the recent analysis of Landau-Aharonov-Casher(LAC) quantization of Ericsson and Sjöqvist[Phys Rev. A {\bf 65} 013607 (2001)]. The energy eigenfuction and eigenvalues are obtained.

quant-ph↗

arXiv2005

Landau Quantization of Neutral Particles in an External Field

The quantum dynamics of an induced electric dipole in the presence of a configuration of crossed electric and magnetic fields is analyzed. This field configuration confines the dipole in a plane and produces a coupling similar to the coupling of a charged particle in the presence of external magnetic field. In this work we investigate the analog of Landau levels in induced electric dipoles in a sistem of neutral particles. The energy levels and eigenfunctions are obtained exactly.

hep-th↗

arXiv2005

Bound states in the dynamics of a dipole in the presence of a conical defect

In this work we investigate the quantum dynamics of an electric dipole in a $(2+1)$-dimensional conical spacetime. For specific conditions, the Schrödinger equation is solved and bound states are found with the energy spectrum and eigenfunctions determined. We find that the bound states spectrum extends from minus infinity to zero with a point of accumulation at zero. This unphysical result is fixed when a finite radius for the defect is introduced.

gr-qc↗

arXiv2004

The self-energy of a charged particle in the presence of a topological defect distribution

In this work we study a charged particle in the presence of both a continuous distribution of disclinations and a continuous distribution of edge dislocations in the framework of the geometrical theory of defects. We obtain the self-energy for a single charge both in the internal and external regions of either distribution. For both distributions the result outside the defect distribution is the self-energy that a single charge experiments in the presence of a single defect.

gr-qc↗

arXiv2004

Holonomy, Aharonov-Bohm effect and phonon scattering in superfluids

In this article we discuss the analogy between superfluids and a spinning thick cosmic string. We use the geometrical approach to obtain the geometrical phases for a phonon in the presence of a vortex. We use loop variables for a geometric description of Aharonov-Bohm effect in these systems. We use holonomy transformations to characterize globally the "space-time" of a vortex and in this point of view we study the gravitational analog of the Aharonov-Bohm effect in this system. We demonstrate that in the general case the Aharonov-Bohm effect has a contribution both from the rotational and the translational holonomy. We study also Berrys quantum phase for phonons in this systems.

gr-qc↗

arXiv2003

Loop variables in the geometry of a rotating black string

In this paper we analyze in the Wilson loop context the parallel transport of vectors and spinors around a closed loop in the background space-time of a rotating black string in order to classify its global properties. We also examine particular closed orbits in this space-time and verify the Mandelstam relations.

gr-qc↗

arXiv2003

Quantum Dynamics of Magnetic and Electric Dipoles and Berry's Phase

We study the quantum dynamics of neutral particle that posseses a permanent magnetic and electric dipole moments in the presence of an electromagnetic field. The analysis of this dynamics demonstrates the appearance of a quantum phase that combines the Aharonov-Casher effect and the He-Mckellar-Wilkens effect. We demonstrate that this phase is a special case of the Berry's quantum phase. A series of field configurations where this phase would be found are presented. A generalized Casella-type effect is found in one these configurations. A physical scenario for the quantum phase in an interferometric experiment is proposed.

quant-ph↗

arXiv2003

Solid State Analog for He-McKellar-Wilkens Quantum Phase

In this letter we investigate the quantum dynamics of a quasiparticle in the presence of a charged screw dislocation submitted to a uniform magnetic field. Analysing the quantum scattering for this quasiparticle we observed the appearance of a topological quantum phase in the solution and demonstrate that this phenomenon is the solid state analog of the He-McKeller-Wilkens effect.

cond-mat.mtrl-sci↗

arXiv2000

Landau Levels in the Presence of Topological Defects

We study the Landau levels associated with electrons moving in a magnetic field in the presence of a continuous distribution of disclinations, a magnetic screw dislocation and a dispiration. We focus on the influence of these topological defects on the spectrum of the electron(or hole) in a magnetic field in the framework of the geometric theory of defects in solids of Katanaev and Volovich. The presence of the defects breaks the degeneracy of the Landau levels in different ways depending on the defect. Exact expressions for energies and eigenfuctions are found for all cases.

quant-ph↗

arXiv1996

Charge localization around disclinations in monolayer graphite

Using a continuum model, we obtain qualitative results that imply charge localization around negative curvature disclinations (i.e. rings with more than 6 Carbon atoms) in a graphite sheet. Conversely, it is found that positive curvature disclinations repel charge, independent of its sign.

cond-mat↗

arXiv1996

Electrostatic self-force in (2+1)-dimensional cosmological gravity

Point sources in (2+1)-dimensional gravity are conical singularities that modify the global curvature of the space giving rise to self-interaction effects on classical fields. In this work we study the electrostatic self-interaction of a point charge in the presence of point masses in (2+1)-dimensional gravity with a cosmological constant.

gr-qc↗