RESUMO
Atom interferometers covering macroscopic domains of space-time are a spectacular manifestation of the wave nature of matter. Because of their unique coherence properties, Bose-Einstein condensates are ideal sources for an atom interferometer in extended free fall. In this Letter we report on the realization of an asymmetric Mach-Zehnder interferometer operated with a Bose-Einstein condensate in microgravity. The resulting interference pattern is similar to the one in the far field of a double slit and shows a linear scaling with the time the wave packets expand. We employ delta-kick cooling in order to enhance the signal and extend our atom interferometer. Our experiments demonstrate the high potential of interferometers operated with quantum gases for probing the fundamental concepts of quantum mechanics and general relativity.
RESUMO
A new invisibility cloak was recently proposed for hiding objects in front of a highly reflecting mirror. This cloak requires only modest values of optical constants with minimal anisotropy and thus can be implemented by using non-resonant dielectric materials, making it an ideal system for optical frequency operation. We implemented the cloak using an array of silicon nanorods fabricated by electron-beam lithography. We then directly visualized the cloaking effect by monitoring the light propagation inside the device using the near-field optical microscopy.
