Detecting k-nonseparability via quantum Fisher information

The k-nonseparability is a kind of multipartite quantum correlation which can be used to characterize some aspects of multipartite entanglement. In this paper, we discuss the detection of k-nonseparability of n-partite quantum states from an information perspective and obtain some k-nonseparability criteria in terms of quantum Fisher information. These criteria can identify many k-nonseparable states, and their advantages over an important and well-known k-nonseparability criterion [M. Huber et al., Phys. Rev. A 88, 042328 (2013)] are illustrated by several typical examples.