The physics-y QM deals with particles, the states of which are wave functions -- vectors in an infinite dimensional Hilbert space. Things like momentum operators are derivatives (in the position basis), normalisation involves integration, etc. The information theory people deal with qubits, the states of which are vectors in finite dimensional spaces -- this simplifies a lot of the maths, whilst retaining the main concepts. Thus my question about what he really wants -- physics, to do with things like tunneling and field theory, or computing, to do with cryptography or teleportation.