A friend has recommended Coecke and Kissinger's book, Picturing Quantum Processes, which takes an alternative conceptual approach to quantum computation based o

A friend has recommended Coecke and Kissinger's book, Picturing Quantum Processes, which takes an alternative conceptual approach to quantum computation based on string diagrams (not-so-secretly a formalism for working with various flavours of monoidal category, as explained in the optional sections) instead of linear algebra.