Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Demonstration of Quantum Key Distribution with Entangled Photons for
  the Undergraduate Laboratory   Now that fundamental quantum principles of indeterminacy and measurement have
become the basis of new technologies that provide secrecy between two
communicating parties, there is a need to provide teaching laboratories that
illustrate how these technologies work. In this article we describe a
laboratory exercise in which students perform quantum key distribution with
single photons, and see how the secrecy of the communication is ensured by the
principles of quantum superposition and state projection. We used a table-top
apparatus, similar to those used in correlated-photon undergraduate
laboratories, to implement the Bennett-Brassard-84 protocol with
polarization-entangled photons. Our experiment shows how the communication
between two parties is disrupted by an eavesdropper. We use a simple quartz
plate to mimic how an eavesdropper intercepts, measures, and resends the
photons used in the communication, and we analyze the state of the light to
show how the eavesdropper changes it.

30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg