Resumen:
In this thesis I present four works developed in collaboration during my PhD. The main
topic in them was the study of correlations in quantum information protocols with particular
emphasis in quantum discord and entanglement.
In the article entitled Quantum Discord Underlies the Optimal Scheme for Modifying the
Overlap between Two States J. Phys. Soc. Jpn. 83, 044006 (2014), we focused on quantum
discord in the context of overlap modification between two non-orthogonal states. We
showed that only discord is necessary to assist the probabilistic and deterministic
protocols for overlap modification.
In the article entitled A measure for maximum similarity between outcome states EPL, 109,
40001 (2015), we developed a new correlation, similarity degree (SD). Like discord, this
quantity characterizes the effect of a local measurement on the other subsystem. We
find and analytical expression to calculate it. Addionally, it can be directly measured
in an optical setup.