Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A controlled ac Stark echo for quantum memories   A quantum memory protocol of controlled ac Stark echoes (CASE) based on a
double rephasing photon echo scheme via controlled Rabi flopping is proposed. A
double rephasing scheme of photon echoes inherently satisfies the no-population
inversion requirement for quantum memories, but the resultant absorptive echo
has been a fundamental problem. In the present studies, firstly, the first echo
in the double rephasing scheme is dynamically controlled not to affect the
second echo by using unbalanced ac Stark shifts. Secondly, a control Rabi pulse
coherently manipulates the second echo to be emissive via controlled coherence
conversion. Owing to far-off resonance of ac Stark fields, the present protocol
can be applied for wavelength-selective dynamic control of quantum memories in
real time for erasing, buffering, and multiplexing.

18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
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The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci