Information-theoretic measure of genuine multiqubit entanglement
Jianming Cai, Zheng-Wei Zhou, Xingxiang Zhou, Guang‐Can Guo · Physical Review A · 2006
We consider pure quantum states of $N$ qubits and study the genuine $N$-qubit entanglement that is shared among all the $N$ qubits. We introduce an information-theoretic measure of genuine $N$-qubit entanglement based on bipartite partitions. When $N$ is an even number, this measure is presented in a simple formula, which depends only on the purities of the partially reduced density matrices. It can be easily computed theoretically and measured experimentally. When $N$ is an odd number, the measure can also be obtained in principle.