Speaker
Prof.
Kevin Resch
(University of Waterloo)
Description
Entanglement is required for most applications in quantum information science. In optics,
the most widespread source of entangled photon pairs is the nonlinear optical process
of parametric down-conversion. Through this process, single high energy pump photons are
converted into pairs of lower energy photons. In the first part of my talk I will describe
our realization of cascaded parametric down-conversion, a sequence of two downconversion
that can produce photon triplets, a longstanding goal of the quantum optics community.
I will describe our experiments to detect the novel form of genuine three-photon
energy-time entanglement produced through this process and the direct production of
polarization Greenberger-Horne-Zeilinger states. In addition to their importance in quantum
technologies, entangled photons can be used to perform fundamental tests of nature, such as
ruling out local hidden variable descriptions. In the second part of my talk, I will discuss
our experimental test of Mermin's inequality: a bound on the strength of correlations
between three particles imposed by such models. We have for the first time closed the
locality loophole in such a test by distributing three-photon entanglement over long
distances using free-space optical links to causally disconnected locations. These results
demonstrate the experimental requirements for implementing practical three-party quantum communication
protocols (joint work with Thomas Jennewein).
Author
Prof.
Kevin Resch
(University of Waterloo)
