Reduction of theoretical uncertainty in quantum computing (Q1805625)

This paper provides a diagramatic method to vizualize and assess limitations due to intrinsic uncertainty inherent in quantum states. Further the authors aim at building quantum circuit algorithms that reduce intrinsic uncertainty to a level low enough so that reduction in operational uncertainty becomes effective. The overall process of quantum computation was thought of as consisting of (i) preparation of register, which is a superposition of the ground and excited states, (ii) row operations generating entangles states, (iii) unitary evolution converging to less dispersive states and (iv) measuring of the final solution state. The less the uncertainty in this state, the more accurately one can read it. The authors have developed a way to estimate intrinsic uncertainties in provisional results of quantum computing. This method could be applied to other quantum computing schemes in addition to the solid-state implementation focused on in this paper.