Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multi-input Schr\"odinger equation: controllability, tracking, and
  application to the quantum angular momentum   We present a sufficient condition for approximate controllability of the
bilinear discrete-spectrum Schr\"odinger equation exploiting the use of several
controls. The controllability result extends to simultaneous controllability,
approximate controllability in $H^s$, and tracking in modulus. The result is
more general than those present in the literature even in the case of one
control and permits to treat situations in which the spectrum of the
uncontrolled operator is very degenerate (e.g. it has multiple eigenvalues or
equal gaps among different pairs of eigenvalues). We apply the general result
to a rotating polar linear molecule, driven by three orthogonal external
fields. A remarkable property of this model is the presence of infinitely many
degeneracies and resonances in the spectrum preventing the application of the
results in the literature.

25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph