Quantum Fisher Information of Schrödinger Cat States

A general expression for the quantum Fisher information (QFI) of atomic Schrödinger cat states is presented. We analyze the dependence of the QFI on the cat state parameters and demonstrate a possibility to achieve the Heisenberg limit scaling of the Ramsey interferometric measurements. Interplay between non-classical correlations between atoms and maximization of QFI of the cat states is discussed.