  We construct quantum gate entanglers for different classes of multipartite
states based on definition of W and GHZ concurrence classes. First, we review
the basic construction of concurrence classes based on orthogonal complement of
a positive operator valued measure (POVM) on quantum phase. Then, we construct
quantum gates entanglers for different classes of multi-qubit states. In
particular, we show that these operators can entangle multipartite state if
they satisfy some conditions for W and GHZ classes of states. Finally, we
explicitly give the W class and GHZ classes of quantum gate entanglers for
four-qubit states.
