Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Noise suppression in a temporal-multimode quantum memory entangled with
  a photon via asymmetrical photon-collection channel   Quantum interfaces (QIs) that generate entanglement between a multimode
atomic memory and a photon forms a multiplexed repeater node and hold promise
to greatly improve quantum repeater rates. Recently, the temporal multimode
spin-wave memory that is entangled with a photon has been demonstrated with
cold atoms. However, due to additional noise generated in multimode operation,
the fidelity of spin-wave-photon entanglement significantly decreases with the
mode number. So far, the improvement on temporal-multimode entanglement
fidelity via suppressing the additional noise remains unexplored. Here, we
propose and experimentally demonstrate a scheme that can suppress the
additional noise of a temporally-multiplexed QI. The scheme uses an asymmetric
channel to collect the photons coming and retrieving from the
temporally-multiplexed QI. For making comparisons, we also set up a QI that
uses symmetric channel for the photon collections. When the QIs store 14 modes,
the measured Bell parameter S for the QIs using the asymmetric and the
symmetric photon-collection channels are 2.36+/-0.03 and 2.24+/-0.04,
respectively, showing that the QI using the asymmetric channel gives rise to a
3% increase in entanglement fidelity, i.e., a 1.7-fold decrease in the
additional noise, compared with the QI using the symmetric one. On the other
hand, the 14-mode entanglement QIs that use the asymmetric and symmetric
collections preserve the violation of a Bell inequality for storage times up to
25 us and 20 us, respectively, showing that the asymmetric QI has a higher
entanglement storage performance.

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The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
1
The categories of this paper are: cs
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The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
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The categories of this paper are: q-fin