  The overarching goal of this thesis is to demonstrate that complementarity is
at the heart of quantum information theory, that it allows us to make (some)
sense of just what information "quantum information" refers to, and that it is
useful in understanding and constructing quantum information processing
protocols. The detailed research results which form the basis of these claims
are to be found in the included papers, and the aim here is to present an
overview comprehensible to a more general audience.
