00796nas a2200169   4500000000100000000000100001000000100002008004100003260000600044100001300050700002200063700001300085245005100098300001500149490000700164520045500171       2007                            d  c91 aJ. Kosik1 aJaroslaw Miszczak1 aV. Buzek00aQuantum Parrondo's game with random strategies  a2275–2280 v543 aWe present a quantum implementation of Parrondo's game with randomly switched strategies using (1) a quantum walk as a source of 'randomness' and (2) a completely positive (CP) map as a randomized evolution. The game exhibits the same paradox as in the classical setting where a combination of two losing strategies might result in a winning strategy. We show that the CP-map scheme leads to significantly lower net gain than the quantum-walk scheme.