We study the all-optical control of the quantum fluctuations of a light beam via a combination of single-atom cavity quantum electrodynamics (CQED) and electromagnetically induced transparency (EIT). Specifically, the EIT control field is used to tune the CQED transition frequencies in and out of resonance with the probe light. In this way, photon blockade and antiblockade effects are employed to produce sub-Poissonian and super-Poissonian light fields, respectively. The achievable quantum control paves the way towards the realization of a prototype of a novel quantum transistor which amplifies or attenuates the relative intensity noise of a light beam. Its feasibility is demonstrated by calculations using realistic parameters from recent experiments.
Systems of interacting classical harmonic oscillators have received considerable attention in the last years as analog models for describing electromagnetically induced transparency (EIT) and associated phenomena. We review these models and investigate their validity for a variety of physical systems using two-and three-coupled harmonic oscillators. From the simplest EIT-Λ configuration and twocoupled single cavity modes we show that each atomic dipole-allowed transition and a single cavity mode can be represented by a damped harmonic oscillator. Thus, we have established a one-toone correspondence between the classical and quantum dynamical variables. We show the limiting conditions and the equivalent for the EIT dark state in the mechanical system. This correspondence is extended to other systems that present EIT-related phenomena. Examples of such systems are two-and three-level (cavity EIT) atoms interacting with a single mode of an optical cavity, and four-level atoms in a inverted-Y and tripod configurations. The established equivalence between the mechanical and the cavity EIT systems, presented here for the first time, has been corroborated by experimental data. The analysis of the probe response of all these systems also brings to light a physical interpretation for the expectation value of the photon annihilation operator a . We show it can be directly related to the electric susceptibility of systems, the composition of which includes a driven cavity field mode.
A química é o ramo da ciência que estuda a matéria e suas propriedades. Os parâmetros curriculares ressaltam que o ensino de química não pode se resumir apenas à transmissão de conhecimento, mas também fazer referência com o cotidiano do aluno de modo a facilitar a assimilação dos conteúdos. Para isso, faz-se uso de representações como materiais macroscópicos, gráficos e experimentos para que fenômenos sejam percebidos por meio de alteração de cores, precipitações, etc. Estes procedimentos geralmente são baseados na percepção visual. Mas e no caso de alunos portadores de deficiência visual? Estes ficariam privados de um ensino de química mais dinâmico e lúdico? Neste trabalho nós apresentamos uma proposta de elaboração de materiais alternativos para levar conteúdos da química de uma forma mais envolvente para estes alunos. A partir da adaptação de imagens, gráficos e ilustrações do capítulo de um livro didático de química nós mostramos que é possível os alunos assimilar conceitos científicos diversos, que a princípio só poderiam ser ensinados a partir da percepção visual. Nós também apresentamos uma sugestão de sequência didática para uso do material desenvolvido baseada em nosso relato de experiência com uma turma de 7 alunos portadores de deficiência visual.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.