http://hdl.handle.net/11422/53 2026-07-30T15:17:04Z http://hdl.handle.net/11422/29860 Title: An introduction to stochastic electrodynamics: motivations, foundations and applications Author(s)/Inventor(s): Silva, Nathália de Abreu Costa da Advisor: Souza, Carlos Farina de Abstract: This dissertation presents an introduction to Stochastic Electrodynamics (SED), a theory that seeks to reinterpret quantum phenomena based on classical principles, postulating the existence of a classical electromagnetic zero-point field (ZPF) with a Lorentz-invariant energy spectrum. The central motivation is to investigate whether this stochastic classical field can be the origin of effects traditionally associated with quantization. The work is divided into three main parts. First, we trace the historical origin of the concept of zero-point energy, from the crisis of classical physics in the face of the blackbody radiation problem – with contributions from Planck, Einstein, Stern, among others – to its initial formulation. Next, we discuss the formal foundations of SED, constructing the zero-point field from Maxwell’s equations and establishing its attributes of randomness, spectrum, and Lorentz invariance. Finally, we present some applications of the theory, focusing on its ability to derive Planck’s spectrum for blackbody radiation and to predict dispersive forces, such as the Casimir force, from classical interactions between matter and the ZPF. We conclude the dissertation by assessing the current scope, extensions, and limitations of SED, highlighting it as a fertile alternative theoretical framework for understanding quantum phenomena. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação 2026-03-05T00:00:00Z http://hdl.handle.net/11422/29715 Title: Dynamical Casimir effects with atoms and spinning nanoparticles Author(s)/Inventor(s): Matos, Guilherme Costa Advisor: Maia Neto, Paulo Américo Abstract: Motivated by recent experiments with levitated, ultra-fast rotating nanoparticles, this thesis presents new effects in the interaction of spinning particles with the quantum vacuum. The first part of the thesis studies the quantum electrodynamical analog of the Sagnac effect, in which the rotation of a neutral particle in the vicinity of an atom interferometer induces a phase on the propagating matter waves. The resulting phase is a geometric Berry phase proportional to the angular velocity of the particle. A rotation confined to a region of space leaving a trace of non-inertiality in an inertial frame suggests an analogy with the Aharonov-Bohm effect. Taking the particle’s plasmon resonances account, the analysis reveals that the phase magnitude is close to the limit of measurement for current state of the art atom interferometers. The force on an atom by a rotating particle is also calculated, and is shown to be analogous to the Coriolis force. The second part of the thesis deals with the photon emission by a rotating non-spherical neutral particle. Provided that the rotation axis is orthogonal to particle symmetry axis, the interaction of the particle with the field produces frequency sidebands of the scattered field, leading to the emission of dynamical Casimir photon pairs. The photon emission rate is obtained for metallic and dielectric spheroids and is enhanced when the rotation frequency is near a plasmonic or polaritonic resonance. In order to optimize the emission rate, the velocity of the particle’s tip is fixed and the dependence with the particle’s geometry is considered. Publisher: Universidade Federal do Rio de Janeiro Type: Tese 2025-12-18T00:00:00Z http://hdl.handle.net/11422/29669 Title: Estudo do espalhamento elástico com feixes exóticos no regime de baixas energias Author(s)/Inventor(s): Souza, Bernard Lucas Brandão Suhett de Advisor: Santos, Antônio Carlos Fontes dos Abstract: In this work, elastic scattering measurements were performed for the 6He + 197Au system at the energies ELab = 18.0, 21.8, and 23.0 MeV, close to the Coulomb barrier (ELab = 19.11 MeV). The angular distributions were analyzed using Woods–Saxon optical potentials, the S˜ao Paulo Potential (SPP), and four-body CDCC calculations, also performed at the energy of 27.0 MeV. Experimental data available in the literature were also analyzed for the systems 6He+ 51V (15.4 and 23.0 MeV), 7Be+51V (26.0 MeV), and 8Li+51V (18.5 and 26.0 MeV), aiming to investigate effects associated with weakly bound nuclei. All experimental measurements were performed at the Radioactive Ion Beams in Brazil (RIBRAS) system, installed at the Pelletron Laboratory of the Institute of Physics of the University of S˜ao Paulo. The results obtained from the 4B-CDCC calculations evidenced the importance of coupling effects associated with the halo nature of the 6He nucleus. The experimental data for the 7Be + 51V system were satisfactorily reproduced by the S˜ao Paulo Potential. On the other hand, the results for the 8Li+51V system demonstrated the relevance of the transfer channel for the description of this interaction. Publisher: Universidade Federal do Rio de Janeiro Type: Tese 2025-12-15T00:00:00Z http://hdl.handle.net/11422/29659 Title: Exploring quantum optics and quantum information: from the interferometer to the generation of correlated photons Author(s)/Inventor(s): Araújo, Jailson Sales Advisor: Aguilar, Gabriel Horacio Abstract: This thesis investigates, in photonics, how to design, diagnose, and exploit open quantum dynamics and light–matter interactions along three complementary fronts. First, we present a programmable interferometer in linear optics in which the path degree of freedom encodes the system and polarization serves as an ancilla qubit to implement Kraus maps; we implement decoherence and dissipation channels (dephasing, amplitude damping, and Pauli), including finite-temperature extensions (GAD/SGAD). Next, using a recently defined quantum-reality quantifier, we demonstrate that Alice’s local operations correlate with the erasure of the reality of observables in Bob’s photon in a scenario of causally disconnected measurements; a modified optical quantum eraser, with entangled pairs and quantum-state tomography, confirms this correlation experimentally. Finally, we investigate the generation and control of Stokes–anti-Stokes correlations in Raman scattering and propose an experimental route to (i) analyze orbital-angular-momentum conservation in this process and (ii) study field-induced anisotropy in polar liquids under a uniform electric field. Publisher: Universidade Federal do Rio de Janeiro Type: Tese 2025-12-16T00:00:00Z