  For donor nuclear spins in silicon, we show how to deterministically prepare
various symmetric and asymmetric Dicke states which span a complete basis of
the many-body Hilbert space. The state preparation is realized by cooperative
pumping of nuclear spins by coupled donor electrons, and the required controls
are in situ to the prototype Kane proposal for quantum computation. This scheme
only requires a sub-gigahertz donor exchange coupling which can be readily
achieved without atomically precise donor placement, hence it offers a
practical way to prepare multipartite entanglement of spins in silicon with
current technology. All desired Dicke states appear as the steady state under
various pumping scenarios and therefore the preparation is robust and does not
require accurate temporal controls. Numerical simulations with realistic
parameters show that Dicke states of 10-20 qubits can be prepared with high
fidelity in presence of decoherence and unwanted dynamics.
