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COLOQUIOS DEL DEPARTAMENTO DE FÍSICA FCEyN - UBA<br>
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<a href="http://coloquios.df.uba.ar/" target="_blank">http://coloquios.df.uba.ar/</a><br>
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Charla, café y galletitas<br>
En el Aula Federman, 1er piso, Pabellón I,<br>
Ciudad Universitaria<br>
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Jueves 15 de septiembre, 14hs,<br>
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NON-LOCAL EFFECTS OF SPATIALLY CORRELATED PHOTONS<br>
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Stephen Walborn<br>
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Universidad Federal de Rio de Janeiro<br>
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The spatial correlations of photon pairs produced by spontaneous parametric<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
down-conversion have been studied for nearly forty years. They appear<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
simultaneously in the complementary near- and far-field transverse variables of the photons. It has been shown that these correlations are<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
quantum-mechanical in nature, and give rise to a number of non-classical<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
effects that could be exploited for improved imaging and metrology, as well<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
as more secure communications. In this seminar I?ll discuss two recent<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
experiments that illustrate several novel non-local aspects of spatial<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
correlations. The first shows that appropriately engineered photons violate a non-locality witness based on entropy functions, which shows that the correlations cannot be described by a local ?classical? model. In the<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
second experiment, an analog of an optical vortex, such as that which<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
appears in a classical optical beam with non-zero orbital angular momentum,<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
is observed in a non-local coordinate plane. In this sense the optical<br style="padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">
vortex appears in the correlations of the photon pairs.<br>
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