A one-dimensional quantum walk with multiple-rotation on the coin
  We introduce and analyze a one-dimensional quantum walk with two time-independent rotations on the coin. We study the influence on the property of quantum walk due to the second rotation on the coin. Based on the asymptotic solution in the long time limit, a ballistic behaviour of this walk is observed. This quantum walk retains the quadratic growth of the variance if the combined operator of the coin rotations is unitary. That confirms no localization exhibits in this walk. This result can be extended to the walk with multiple time-independent rotations on the coin. 
Peng Xue, Rong Zhang, Hao Qin, Xiang Zhan, Zhihao Bian, and Jian Li
quant-ph