  We introduce a potential of multipartite entanglement for a system of n
qubits, as the average over all balanced bipartitions of a bipartite
entanglement measure, the purity. We study in detail its expression and look
for its minimizers, the maximally multipartite entangled states. They have a
bipartite entanglement that does not depend on the bipartition and is maximal
for all possible bipartitions. We investigate their structure and consider
several examples for small n.
