Abstract

Application of continuous feedback control to the center of mass of a bosonic gas is shown to induce a breathing of the atomic cloud. The amplitude of the breathing depends on initial atom-atom correlations and can thus be directly used for characterizing the quantumness of the atom-atom correlations. Two levels of quantumness appear in the form of a single-atom quadrature squeezing and of a violation of the classical Schwarz inequality. © Nauka/Interperiodica 2006.