Propagation of the information in a one-way quantum computer

Abstract

Both linear momentum and Poynting vector associated with the propagation of information in a one-way quantum computer are studied. It is found that, within the so-called Mean Field Theory (MFT) approximation the total energy, the linear momentum and the Poynting vector associated with the propagation of information are invariant under arbitrary rotations of logical qubits. This means that propagation of the quantum information stored in the entangled state does not depend on the choice of the quantum gates. Due that the involved cluster of neighboring particles is large enough, last property satisfies the scalability test. As a consequence, quantum information in the one-way computer is read, written and processed independently of this choice, which suggests a simple hardware for it. When an external magnetic field is switched on, the invariance under arbitrary rotations of the logic qubits of these quantities is lost, that is, the field induces a preferential direction of propagation of the information which at the same time is optimized while more intense be the field.