“…The literature on repeated interaction systems we are aware of can be classified into two categories. In a first one, effective evolution equations are derived by taking continuous interaction limits [5,6,2,3,33,34,21] and in a second category, the dynamics is left discrete, but the time-asymptotics is investigated [11,12,13,14,8,9,22,31]. To our knowledge, repeated interaction systems have been first proposed in [27,28] and in [5,6] as approximations for system-environment type models, where it is proven that the discrete evolution converges to that of a quantum Langevin equation, in the limit of ever shorter system-probe interaction times.…”