We consider the separability of various joint states for N qutrits. We deri
ve two results: (i) the separability condition for a two-qutrit state that
is a mixture of the maximally mixed state and a maximally entangled state (
such a state is a generalization of the Werner state for two qubits); (ii)
upper and lower bounds on the size of the neighborhood of separable states
surrounding the maximally mixed state for N qutrits. (C) 2000 Elsevier Scie
nce B.V. All rights reserved.