Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Possibilities of the Quantum Memory Realization for Short Pulses of
  Light in the Photon Echo Technique   The possibilities of recording, storage and reconstruction of short single
photon wave packets in the photon echo technique are analyzed. The influence of
the photon field and medium parameters on the quality and precision of the
photon quantum state reconstruction is theoretically studied.

12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol