A total measure of multi-particle quantum correlations in atomic Schr'odinger cat states

摘要

We propose a total measure of multi-particle quantum correlation in a systemof N two-level atoms (N qubits). We construct a parameter that encompasses allpossible quantum correlations among N two-level atoms in arbitrary symmetricpure states and define its numerical value to be the total measure of the netatom-atom correlations. We use that parameter to quantify the total quantumcorrelations in atomic Schr\"{o}dinger cat states, which are generated by thedispersive interaction in a cavity. We study the variation of the net amount ofquantum correlation as we vary the number of atoms from N=2 to N=100 and obtainsome interesting results. We also study the variation of the net correlation,for fixed interaction time, as we increase the number of atoms in the excitedstate of the initial system, and notice some interesting features. We alsoobserve the behaviour of the net quantum correlation as we continuouslyincrease the interaction time, for the general state of N two-level atoms in adispersive cavity.