  Quantum devices, from simple fixed-function tools to the ultimate goal of a
universal quantum computer, will require high quality, frequent repetition of a
small set of core operations, such as the preparation of entangled states.
These tasks are perfectly suited to realisation by a co-processor or
supplementary instruction set, as is common practice in modern CPUs. In this
paper, we present two quintessentially quantum co-processor functions:
production of a GHZ state, and implementation of optimal universal (asymmetric)
quantum cloning. Both are based on the evolution of a fixed Hamiltonian. We
introduce a new technique for deriving the parameters of these Hamiltonians
based on the numerical integration of Toda-like flows.
