00974nas a2200109   4500008004300000245008900043210006900132260003400201520057100235100002200806856003600828       2003                        en_Ud  00aControllability properties for finite dimensional quantum Markovian master equations0 aControllability properties for finite dimensional quantum Markov  bAmerican Institute of Physics3 aVarious notions from geometric control theory are used to characterize the behavior of the Markovian master equation for N-level quantum mechanical systems driven by unitary control and to describe the structure of the sets of reachable states. It is shown that the system can be accessible but neither small-time controllable nor controllable in finite time. In particular, if the generators of quantum dynamical semigroups are unital, then the reachable sets admit easy characterizations as they monotonically grow in time. The two level case is treated in detail.1 aAltafini, Claudio  uhttp://hdl.handle.net/1963/2909