Emaranhamento térmico e coerência quântica de um único elétron em um ponto quântico duplo com interação Rashba

Abstract

In recent years, the improvement of materials production techniques allowed great advances and applications among electronic devices, due to manipulations on the charge and/or spin of electrons. One of these applications are low-dimensional systems, in particular, quantum dots, whose main characteristic is the confinement of the electron in three spatial dimensions. This dissertation proposes the study of thermal quantum coherence in a double semiconductor quantum dot. Here we consider a single electron in a double quantum dot with spin-orbit Rashba interaction in the presence of an external magnetic field. Analytical expressions for thermal concurrency and correlated coherence are obtained using the density matrix formalism. The main objective of this dissertation is to provide a good understanding of the effects of temperature, the tunneling parameter, the Rashba effect and Zeeman splitting on quantum coherence. Furthermore, our results show that we can use Rashba coupling to tune the thermal entanglement and quantum coherence of the system. And finally, we focus on the role played by thermal entanglement and the correlated coherence responsible for quantum correlations. We observe that correlated coherence is more robust than thermal entanglement, so quantum algorithms based only on correlated coherence can be stronger than those entanglement based.