  In our previous works, we have studied quantum random walk search algorithm
on hypercube, with traversing coin constructed by using generalized Householder
reflection and a phase multiplier. When the same phases are used each
iteration, the algorithm is robust (stable against errors in the phases) if a
certain connection between the phases in the traversing coin is preserved,
otherwise small errors lead to poor algorithm performance. Here we investigate
how the robustness changes if different phases are used, depending on the
current iteration number. We numerically study six different examples with
different phase sequences. We show that usage of a particular sequence of
phases can make the algorithm more robust even if there is no preserved
connection between the phases in the traversing coin.
