Equivalent Quantum Circuits
  Quantum algorithms and protocols are often presented as quantum circuits for a better understanding. We give a list of equivalence rules which can help in the analysis and design of quantum circuits. As example applications we study quantum teleportation and dense coding protocols in terms of a simple XOR swapping circuit and give an intuitive picture of a basic gate teleportation circuit. 
Juan Carlos Garcia-Escartin and Pedro Chamorro-Posada
quant-ph