arXiv subjects

Rafael A. de Oliveira

Publications and source records attributed to Rafael A. de Oliveira.

3 recordsLinked to original sources

arXiv2022

An experimental analysis from the magnetic interactions in nanowire arrays

We study the magnetic interactions experimentally in nanostructures of nanowire arrays. The intensity value obtained from the interactions provides information about its magnetic behavior. We observed two types of experimental magnetic behavior, i. e., demagnetized and magnetized. Our approach represents the first experimental way to analyze the magnetic behavior of a nanostructure considering its magnetic dependence, which is very important for applications in sensors, for example.

cond-mat.mes-hall↗

arXiv2020

Nonlinear system synchronization to sum signals of multiple chaotic systems

Coupling of chaotic oscillators has evidenced conditions where synchronization is possible, therefore a nonlinear system can be driven to a particular state through input from a similar oscillator. Here we expand this concept of control of the state of a nonlinear system by showing that it is possible to induce it to follow a \textit{linear} superposition of signals from multiple equivalent systems, using only partial information from them, through one- or more variable-signal. Moreover, we show that the larger the number of trajectories added to the input signal, the better the convergence of the system trajectory to the sum input.

nlin.AO↗

arXiv2014

Single-Photon Superradiance in Cold Atoms

The interaction of an ensemble of atoms with common vacuum modes may lead to an enhanced emission into these modes. This phenomenon, known as superradiance, highlights the coherent nature of spontaneous emission, resulting in macroscopic entangled states in mundane situations. The complexity of the typical observations of superradiance, however, masks its quantum nature, allowing alternative classical interpretations. Here we stress how this picture changed with the implementation ten years ago of a new process for single-photon generation from atomic ensembles. We present then the last piece of evidence for the superradiant nature of such process, reporting the observation of an accelerated emission of the photon with a rate that may be tuned by controllably changing the number of atoms in the ensemble. Such investigation paves the way to a new, bottom-up approach to the study of superradiance.

quant-ph↗