The Bridge - February 2018 - 7

Quantum entanglement is the property linking two
(or more) particles with properties that can only
be described jointly, going far beyond any classical
correlation, and existing simultaneously across
multiple bases. Entanglement first came to light in
the now-famous 1935 EPR paper in which Einstein
and colleagues used it to try to explain why quantum
mechanics was an incomplete theory. At that time,
however, not only was there no experimental way
to generate such particles, there was also not a
theoretical way to differentiate Einstein's claims from
those of quantum theory. In the 1950s, John Bell
developed a formalism that could distinguish the two
viewpoints, but experimental techniques had still not
caught up. Finally, in the early 1970s John Clauser
performed the first experiment to show that indeed
quantum mechanics was correct (and this has
since been verified by experiment after experiment,
continually becoming more precise and more free
of interpretive loopholes; I personally had the honor
in the early 2000s of being a part of the team that
finally did the experiment directly as envisioned in
the original EPR paper). Now that entanglement is
widely accepted and relatively easy to achieve in
the laboratory, its "spooky" properties have opened
up a wide variety of applications, including imaging,
communications, computing, cryptography,
and more.

The goal of this issue is to get you excited about
the importance of quantum entanglement to the
future of technology and electrical engineering,
possibly prompting some of you to get involved
in these areas. The articles introduce some of the
basics of quantum entanglement and a few of
the technologies stemming from it. The first paper
discusses some of the current practical challenges to
quantum computers, along with a possible solution
using another key technology, frequency combs.
The second paper discusses the theory and reality
of quantum cryptography, and addresses a possible
real-world challenge that needs to be considered.
Finally, the last paper gives an introduction to
quantum teleportation, showing that it is not only
reality, but also the basis for many of the other
technologies. Enjoy this glimpse into the world of
quantum entanglement, and hopefully many of you
will join the effort of engineering the future.

Sean J. Bentley earned his BSEE ('95) and MSEE ('97) from the University of Missouri-Rolla (now Missouri University of Science
and Technology), and his Ph.D. in Optics ('04) from the University of Rochester. He is an Associate Professor of Physics at Adelphi
University, where he was awarded the Teaching Excellence Award for 2012-13. From 2014-2016, he served as Director of the
Society of Physics Students and Sigma Pi Sigma (the physics honor society) at the American Institute of Physics. He is authoring a
text on quantum imaging and holds a patent in nonlinear lithography. He is a member of the IEEE Photonic Society, and was elected
to membership in IEEE-HKN as an undergraduate.

HKN.ORG

http://www.HKN.ORG

Table of Contents for the Digital Edition of The Bridge - February 2018