Defesa de tese de doutorado

Resumo

In this thesis we investigate the two-quanta spontaneous emission (TQSE) phenomenon and the Casimir effect in low-dimensional materials. The first two chapters are dedicated to the theoretical study of one- and two-quanta spontaneous emission and the Purcell effect, including some applications that prepare the reader to better understand the subsequent discussion of TQSE near two-dimensional plasmonic materials. Chapter 3 is dedicated to the proposal of novel material platforms to harness the two-quanta decay and emission spectrum of a quantum emitter. First, we consider carbon nanotubes and graphene coated wires. We show how the efficient plasmon-emitter coupling offered by these systems substantially enhance the TQSE in the near-field through the plasmon-plasmon decay channel. We then investigate the TQSE in atomically thin plasmonic nanostructures, which not only provide an extreme enhancement of the decay rate of a quantum emitter, but also efficient generation of entangled photons and frequency selection due to the finite size of the materials. In chapter 4 we start the discussion of the Casimir effect, presenting its general theory and well-known applications. In chapter 5 we introduce topological insulators as excellent systems to achieve tunable Casimir forces, including changing its sign. We then consider the Casimir effect between graphene family materials and show how their topological features, together with the quantum Hall effect, enable fine control of the force with external agents. We end the thesis with the conclusions and final remarks.