Aspects of active quantum vacua: analogue models and quantization in dispersive media

• Ano de defesa: 2020
• Autor(a) principal: Ribeiro, Caio Cesar Holanda
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Active dispersive media; Analogue models; Despertar do vácuo; Materiais dispersivos ativos; Modelos análogos; Vacuum awakening
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/76/76131/tde-28052020-103825/

This is a work about the quantum vacuum. Particularly, unstable vacuum states. These are modified (with respect to Minkowski) vacuum states in which the vacuum polarization effects are so extreme that they eventually dominate the system evolution — a mechanism called vacuum awakening in the gravitational scenario. In this doctoral thesis, we are interested in studying further this phenomenon. We shall focus on interactions between fields and matter that can trigger this sort of instability in two different contexts: analogue models for the vacuum awakening and quantum aspects of active dispersive media. In the former, we shall see that the electromagnetic field in the presence of anisotropic materials behaves as if it were nonminimally coupled to gravity, and we use this analogy to study a couple of scenarios where instability takes place. As for the latter, we shall establish a Lagrangian microscopic model for the interaction between field and matter that gives rise to an effective tachyonic mass, and motivated by this model, we shall quantize the electromagnetic field in the presence of bilayer systems that can sustain instability. Our findings include the appearance of long-range correlations and a new kind of quantum levitation.