We discuss a simple variant of the one-way quantum computing model [R. Raussendorf and H.-J. Briegel, PRL 86, 5188, 2001], called the Pauli measurement model, where measurements are restricted to be along the eigenbases of the Pauli X and Y operators, while auxiliary qubits can be prepared both in the $\ket{ +_{ \pi\over 4}}:={ 1/\sqrt{ 2}}(\ket{ 0}+e^{ i{ \pi\over 4}}\ket{ 1})$ state, and the usual $\ket{ +}:={ 1/ \sqrt{ 2}}(\ket{ 0}+\ket{ 1})$ state. We prove the universality of this quantum computation model, and establish a standardization procedure which permits all entanglement and state preparation to be performed at the beginning of computation. This leads us to develop a direct approach to fault-tolerance by simple transformations of the entanglement graph and preparation operations, while error correction is performed naturally via syndrome-extracting teleportations.
Categories: quant-ph