Experimental study of non-classicality indicators and extremal quantum correlations in two-qubit states

The study of the connections between entanglement and non-classicality has seen an increasing interest in the last few years. Several forms of entanglement witnesses have been proposed to reveal and quantify the entangle ment of a particular state or a particular class of states. Non-classicality indicators have been proposed so as to quantify quantum correlations in two-qubit states. It has been demonstrated that there are interesting situations in which non-entangled states (i.e. separable) can behave in a non-classical way.