Correlation criteria for Bell type inequalities and entanglement   detection
  We provide a novel criterion for identifying quantum correlation, which allows us to find connections between Bell type inequalities, entanglement detection, and correlation. We utilize the criterion to construct witness operators that can detect genuine multi-qubit entanglement with fewer local measurements. The connection between identifications of quantum correlation and Mermin's inequality is discussed. Detection of genuine four-level tripartite entanglement with two local measurement settings is shown in the same manner. Further, through the criterion of quantum correlation, we derive a new Bell inequality for arbitrary high-dimensional bipartite systems, which requires fewer analyses of the measured outcomes. 
Che-Ming Li, Li-Yi Hsu, Wei-Yang Lin, Yueh-Nan Chen, Der-San Chuu, and   Tobias Brandes