Using semiconducting nanocrystals, a team of scientists from the Hebrew University of Jerusalem has developed a way in which one nanocrystal can be positioned accurately on top of a specially designed and fabricated nano antenna.
“This research paves a promising route for a high purity, high efficiency, on chip single photon source operating at room temperature; a concept that can be extended to many types of quantum emitters,” said Professor Ronen Rapaport. “A highly directional single photon source could lead to a significant progress in producing compact, cheap, and efficient sources of quantum information bits for future quantum technological applications.”
In the same way large antennas on rooftops direct the emission of radio waves, the nano antenna directs single photons emitted from the nanocrystals in a well defined direction. The device produced a highly directional stream of single photons, all flowing in the same direction with low divergence. The photons were then collected with a simple optical setup and sent to be detected and analysed using single photon detectors.
The antennas, which featured simple metallic and dielectric layers, were made using methods compatible with current technologies. Many such devices can be fabricated on one chip, says the team, which is now working on improved devices that will allow deterministic production of single photons straight from the chip into optical fibres.
