Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical non-reciprocity of cold atom Bragg mirrors in motion   Reciprocity is fundamental to light transport and is a concept that holds
also in rather complex systems. Yet, reciprocity can be switched off even in
linear, isotropic and passive media by setting the material structure into
motion. In highly dispersive multilayers this leads to a fairly large
forward-backward asymmetry in the pulse transmission. Moreover, in multilevel
systems, this transport phenomenon can be all-optically enhanced. For atomic
multilayer structures made of three-level cold Rubidium 87 atoms, for instance,
forward-backward transmission contrast around 95 per cent can be obtained
already at atomic speeds in the meter per second range. The scheme we
illustrate may open up avenues for optical isolation that were not previously
accessible.

16
The categories of this paper are: stat
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The categories of this paper are: nucl-ex
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The categories of this paper are: econ
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: eess
31
The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
10
The categories of this paper are: q-bio