Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Linking the rotation of a rigid body to the Schr\"odinger equation: The
  quantum tennis racket effect and beyond   The design of efficient and robust pulse sequences is a fundamental
requirement in quantum control. Numerical methods can be used for this purpose,
but with relatively little insight into the control mechanism. Here, we show
that the free rotation of a classical rigid body plays a fundamental role in
the control of two-level quantum systems by means of external electromagnetic
pulses. For a state to state transfer, we derive a family of control fields
depending upon two free parameters, which allow us to adjust the efficiency,
the time and the robustness of the control process. As an illustrative example,
we consider the quantum analog of the tennis racket effect, which is a
geometric property of any classical rigid body. This effect is demonstrated
experimentally for the control of a spin 1/2 particle by using techniques of
Nuclear Magnetic Resonance. We also show that the dynamics of a rigid body can
be used to implement one-qubit quantum gates. In particular, non-adiabatic
geometric quantum phase gates can be realized based on the Montgomery phase of
a rigid body. The robustness issue of the gates is discussed.

7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph