Spin Squeezing in Superpositions of GHZ State and W States

We investigate the spin squeezing in superpositions of a N-qubit GHZ state and two W states. The spin squeezing parameter is determined by the superposition coefficients and the relative phase. It is shown that there is squeezing in the n ₂ direction and there is no squeezing in the n ₁ direction. It is also shown that the state with more number of qubits has smaller spin squeezing parameter.