382 research outputs found
Controllability of quantum mechanical systems by root space decomposition of su(N)
The controllability property of the unitary propagator of an N-level quantum
mechanical system subject to a single control field is described using the
structure theory of semisimple Lie algebras. Sufficient conditions are provided
for the vector fields in a generic configuration as well as in a few degenerate
cases.Comment: 11 pages, revtex
Controllability properties for finite dimensional quantum Markovian master equations
Various 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.Comment: 15 page
The Symplectic Structure of Curves in Three Dimensional Spaces of Constant Curvature and the Equations of Mathematical Physics
The Coming of World War Three, Volume I: From Protest to Resistance/The International War System, Dimitrios I. Roussopoulos
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