Time-averaged limit measure of the Wojcik model
Takako Endo, Norio Konno · Quantum Information and Computation · 2015
We investigate ``the Wojcik model" introduced and studied by Wojcik et al. \cite{wojcik}, which is a one-defect quantum walk (QW) having a single phase at the origin. They reported that giving a phase at one point causes an astonishing effect for localization. Three types of measures have important roles in the study of QWs: time-averaged limit measure, weak limit measure, and stationary measure. The first two measures imply a coexistence of localized behavior and the ballistic spreading in the QW. As Konno et al. \cite{segawa} suggested, the time-averaged limit and stationary measures are closely related to each other for some QWs with one defect. In this paper, we focus on a relation between the two measures for the Wojcik model. The stationary measure was already obtained by our previous work \cite{watanabe}. Here, we get the time-averaged limit measure by several methods. Our results show that the stationary measure is a special case of the time-averaged limit measure.