Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 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.

20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin