  We study entanglement and spin squeezing in the ground state of three qubits
interacting via the transverse Ising model. We give analytical results for the
entanglement and spin squeezing, and a quantitative relation between the
concurrence, quantifying the entanglement of two spins, and the spin squeezing
parameter, measuring the degree of squeezing. Finally, by appropriately
choosing the exchange interaction and strengths of the transverse field, we
propose a scheme for generating entangled W state from an unentangled initial
state with all spins down.
