arXiv subjects

Thiago Prudencio

Publications and source records attributed to Thiago Prudencio.

12 recordsLinked to original sources

arXiv2017

Non-orthogonality and $κ$-dependence eccentricity of polarized electromagnetic waves in CPT-even Lorentz violation

We discuss the modified Maxwell action of a $K_{F}$-type Lorentz symmetry breaking theory and present a solution of Maxwell equations derived in the cases of linear and elliptically polarized electromagnetic waves in the vacuum of CPT-even Lorentz violation. We show in this case the Lorentz violation has the effect of changing the amplitude of one component of the magnetic field, while leaving the electric field unchanged, leading to non-orthogonal propagation of eletromagnetic fields and dependence of the eccentricity on $κ$-term. Further, we exhibit numerically the consequences of this effect in the cases of linear and elliptical polarization, in particular, the regimes of non-orthogonality of the electromagnetic wave fields and the eccentricity of the elliptical polarization of the magnetic field with dependence on the $κ$-term.

physics.gen-ph↗

arXiv2017

Peccei-Quinn Transformations and Black Holes : Orbit Transmutations and Entanglement Generation

In a recent paper [Mod. Phys. Lett. A30 (2015) 1550104], the black-hole/qubit correspondence (BHQC) was exploited to define "black hole quantum circuits" allowing for a change of the supersymmetry-preserving features of electromagnetic charge configurations supporting the black hole solution, thus switching from one U-duality orbit to another, or - equivalently - from an element of the corresponding Freudenthal Triple System with a definite rank, to another one. On the supergravity side of BHQC, such quantum gates relate to particular symplectic transformations acting on the black hole charges; namely, such transformations cannot belong to the U-duality group, otherwise switching among orbits would be impossible. In this paper, we consider a particular class of such symplectic transformations, namely the ones belonging to the so-called Peccei-Quinn symplectic group, introduced some time ago within the study of very special Kaehler geometries of the vector multiplets' scalar manifolds in N = 2 supergravity in D = 4 space-time dimensions.

hep-th↗

arXiv2017

Optical and spin-optical superpositions modulated by Aharonov-Bohm effect

Generation of Aharonov-Bohm (AB) phase has achieved a state-of-the-art in mesoscopic systems with manipulation and control of the AB effect. The possibility of transfer information enconded in such systems to non-classical states of light increases the possible scenarios where the information can be manipulated and transfered. In this paper we propose a quantum transfer of the AB phase generated in a spintronic device, a topological spin transistor (TST), to an quantum optical device, a coherent state superposition in high-Q cavity and discuss optical and spin-optical superpositions in the presence of an AB phase. We demonstrate that the AB phase generated in the TST can be transfered to the coherent state superposition, considering the interaction with the spin state and the quantum optical manipulation of the coherent state superposition. We show that these cases provide examples of two-qubit states modulated by AB effect and that the phase parameter can be used to control the degree of rotation of the qubit state. We also show under a measurement on the spin basis, an optical one-qubit state that can be modulated by the AB effect. In these cases, we consider a dispesive interaction between a coherent state and a spin state with an acquired AB phase and also discuss a dissipative case where a given Lindblad equation is achieved and solved. Keywords: Quantum transfer; Aharonov-Bohm phase; Spintronics; Quantum Optical Devices.

quant-ph↗

arXiv2016

Singularity transition in a Yukawa-Reissner-Nordström spacetime

A screened charge by a Yukawa potential implies that the corresponding electric field is assimptotically zero far away from a small radius scaling. Considering a screened charge, we have a modified metric of type Yukawa-Reissner-Nordström spacetime, that assimptotically decays from a Reissner-Nordström spacetime to a Schwarzschild spacetime. This implies that the singularity is screened by distance reducing from two singularities to one single singularity for a suitable distance. We consider the tetrad fields associated to the Yukawa-Reissner-Nordström spacetime and show that a linear motion in the proper time lead to suitable estimatives to the Yukawa screening parameter associated to a Schwarzschild radius.

physics.gen-ph↗

arXiv2015

Black hole qubit correspondence from quantum circuits

We consider the black hole qubit correspondence (BHQC) from quantum circuits, taking into account the use of gate operations with base in the formulation of wrapped brane qubits. We interpret these quantum circuits with base on the BHQC classification of entanglement classes and apply in specific examples as the generation of Bell, GHZ states, quantum circuit teleportation and consider the implementation of interchanges in SUSY, black hole configurations, Freudenthal and rank system constructions. These results are discussed from the superstring viewpoint showing that the importance of the construction of the physical states formed by the entanglement of geometrical entities by cohomological operations automatically allows the preservation of different amounts of SUSY in the compactification process given an alternative to the case when fluxes are introduced in the game: the generalized Calabi-Yau of Hitchin.

quant-ph↗

arXiv2015

Cutoff-independent RG flow equations for two-coupled chains model

One-dimensional strongly correlated electron systems coupled via transverse hopping and presence of interband interactions can converge to a Luttinger liquid state or diverge to an even more intricate behavior, as a Mott state. Explicit consideration of the renormalization group (RG) flow of the Fermi points in the Fermi surface, turns the classification of phase transitions more challenging. We reconsider the recent paper for the spinless case [E. Correa and A. Ferraz, Eur. Phys. J. B 87 (2014) 51], where RG flow equations are derived in a cutoff-dependent form up to two-loops order. We demonstrate that the cutoff-dependence can be removed by rewriting the RG flow equations in terms of the energy scale variable. In our paper, the RG flow equations assume a cutoff-independent form and leads to fixed points independent of cutoff choice. The consequence is the invariance under cutoff transformations, more suitable for classifying universality classes and phase transitions.

cond-mat.str-el↗

arXiv2014

Quantum Gravity: physics from supergeometries

We show that the metric (line element) is the first geometrical object to be associated to a discrete (quantum) structure of the spacetime without necessity of black hole-entropy-area arguments, in sharp contrast with other attempts in the literature. To this end, an emergent metric solution obtained previously in [Physics Letters B 661, 186-191 (2008)] from a particular non-degenerate Riemmanian superspace is introduced. This emergent metric is described by a physical coherent state belonging to the metaplectic group Mp (n) with a Poissonian distribution at lower n (number basis) restoring the classical thermal continuum behaviour at large n (n ! 1), or leading to non-classical radiation states, as is conjectured in a quite general basis by mean the Bekenstein- Mukhanov effect. Group-dependent conditions that control the behavior of the macroscopic regime spectrum (thermal or not), as the relationship with the problem of area / entropy of the black hole are presented and discussed.

hep-th↗

arXiv2014

Entanglement And Non-Trivial Topologies

We consider states defined on non-trivial topologies of Torus, Mobius and Torus-Mobius. Adequate operators leading to the construction of coherent states, two-mode coherent states and entangled states are derived and we show a class of entangled states on Torus that are related to the entanglement of photons by orbital angular momentum states.

quant-ph↗

arXiv2014

Goldbach conjecture sequences in quantum mechanics

We show that there is a correspondence between Goldbach conjecture sequences (GCS) and expectation values of the number operator in Fock states. We demonstrate that depending on the normalization or not of Fock state superpositions, we have sequences that are equivalent and sequences that are not equivalent to GCS. We propose an algorithm where sequences equivalent to GCS can be derived in terms of expectation values with normalized states. Defining states whose projections generate GCS, we relate this problem to eigenstates of quantum harmonic oscillator and discuss Fock states directly associated to GCS, taking into account the hamiltonian spectrum and quantum vacuum fluctuations. Finally, we address the problems of degeneracy, maps associating GCS and Goldbach partitions.

physics.gen-ph↗

arXiv2012

Parametric down conversion of a bosonic thermofield vacuum

We consider a process of parametric down conversion where the input state is a bosonic thermofield vacuum. This state leads to a parametric down conversion, generating an output of two excited photons. Following a thermofield dynamics scheme, the input state, initially in a bosonic thermofield vacuum, and the output states, initially in vacuum states, evolve under a Liouville-von Neumann equation.

quant-ph↗

arXiv2012

No-cloning theorem in thermofield dynamics

We discuss the relation between the no-cloning theorem from quantum information and the doubling procedure used in the formalism of thermofield dynamics (TFD). We also discuss how to apply the no-cloning theorem in the context of thermofield states defined in TFD. Consequences associated to mixed states, von Neumann entropy and thermofield vacuum are also addressed.

quant-ph↗

arXiv2011

Quantum information transfer in degenerate Raman regime

The interaction of a three level Rydberg atom of Lambda-type with a single mode optical field in far off-resonant and at large detuning regimes can be described by an effective degenerate Raman model, where the atomic state can be treated as a two-level system of degenerate states. By means of this approximation, we propose a quantum information transfer of an one-qubit state from a Rydberg atom of Lambda-type with degenerate levels to a single-mode field initially in a coherent state.

quant-ph↗