Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hong-Ou-Mandel interference of polarization qubits stored in independent
  room-temperature quantum memories   First generation quantum repeater networks require independent quantum
memories capable of storing and retrieving indistinguishable photons to perform
quantum-interference-mediated high-repetition entanglement swapping operations.
The ability to perform these coherent operations at room temperature is of
prime importance in order to realize large scalable quantum networks. Here we
address these significant challenges by observing Hong-Ou-Mandel (HOM)
interference between indistinguishable photons carrying polarization qubits
retrieved from two independent room-temperature quantum memories. Our
elementary quantum network configuration includes: (i) two independent sources
generating polarization-encoded qubits; (ii) two atomic-vapor dual-rail quantum
memories; and (iii) a HOM interference node. We obtained interference
visibilities after quantum memory retrieval of $\rm
\boldsymbol{V=(41.9\pm2.0)\%}$ for few-photon level inputs and $\rm
\boldsymbol{V=(25.9\pm2.5)\%}$ for single-photon level inputs. Our prototype
network lays the groundwork for future large-scale memory-assisted quantum
cryptography and distributed quantum networks.

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The categories of this paper are: eess
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The categories of this paper are: stat
32
The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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The categories of this paper are: supr-con
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The categories of this paper are: math
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The categories of this paper are: adap-org