Transferência de estado quântico em cadeias de spin

Abstract

Quantum communication consists in transferring quantum states from one place to another. One of its most well known applications is quantum key distribution, in which a random secret key with security guaranteed by the No-Cloning theorem can be established by distant parties. Another utility that has been increasing in relevance is the area of quantum information processing, namely quantum computation, where the connection between two processors is necessary to make quantum computers. To realize these devices, it is needed not only to conceive the quantum state transfer, but also to map how this happens between two distinct quantum processors that send and receive information. In this monograph we will study quantum state transfer in permanently coupled spin chains as well as the fidelity of the transferred information through the natural dynamics of the system.