  We consider two independent quantum walks on separate lines augmented by
partial or full swapping of coins after each step. For classical random walks,
swapping or not swapping coins makes little difference to the random walk
characteristics, but we show that quantum walks with partial swapping of coins
have complicated yet elegant inter-walker correlations. Specifically we study
the joint position distribution of the reduced two-walker state after tracing
out the coins and analyze total, classical and quantum correlations in terms of
the mutual information, the quantum mutual information, and the
measurement-induced disturbance. Our analysis shows intriguing quantum features
without classical analogues.
