• quantum communication theory
• quantum information theory

Quantum Information Theory (QIT) is a relatively new field of physics that is attracting a growing number of researchers.
The new framework provided by the QIT allowed for the study of open systems, i.e. systems subject to external noise; this paved the way for an information theoretic approach to the study of quantum processes relevant to Quantum Computation and Quantum Communication, in the same way Shannon's noisy channel theorem did for classical communication and computation.
This Thesis analyzes the effects that a particular type of noise, which induces energy losses, has on the sharing of quantum information encoded in qudits (i.e. the d-dimensional equivalent of a qubit) between two parties. The effective model for this type of noise is provided by a family of channels called Multi-level Amplitude Damping (MAD) channels, which generalize the well known case of Amplitude Damping Channels to d-dimensional systems.
This analysis is performed through the study of two capacity functionals: the quantum capacity and the 2-way capacity.