Simulation of entanglement generation and variation in quantum computation

Entanglement generation and variation in quantum computation is studied using a quantum computer simulator. The simulator is described and its block diagram is presented. The use of this simulator allows the study of entanglement manipulation in quantum computations that comprise more than two qubits and a variety of quantum gates such as Hadamard, Controlled-Not, Controlled-controlled-Not, Controlled-phase and Fredkin gates. Simulations of entanglement variation in four-qubit and six-qubit quantum Fourier transforms with entangled initial states is also studied.