2004/03/23 by Hiroo Azuma
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.70.012318
published as Phys. Rev. A 70, 012318 (2004) · 11 pages, 7 figures, LaTex2e
arxiv created 2004/03/23 · arxiv updated 2009/12/01
In this paper, we study the quantum computation realized by an interaction-free measurement (IFM). Using Kwiat et al.'s interferometer, we construct a two-qubit quantum gate that changes one particle's trajectory according to whether or not the other particle exists in the interferometer. We propose a method for distinguishing Bell-basis vectors, each of which consists of a pair of an electron and a positron, by this gate. (This is called the Bell-basis measurement.) This method succeeds with probability 1 in the limit of N → ∞, where N is the number of beam splitters in the interferometer. Moreover, we can carry out a controlled-NOT gate operation by the above Bell-basis measurement and the method proposed by Gottesman and Chuang. Therefore, we can prepare a universal set of quantum gates by the IFM. This means that we can execute any quantum algorithm by the IFM.