One of the most important challenges in modern quantum optical applications is the demonstration of efficient, scalable, on-chip single photon sources, which can operate at room temperature. In this paper we demonstrate a room-temperature single photon source based on a single colloidal nanocrystal quantum dot positioned inside a circular bulls-eye shaped hybrid metal-dielectric nanoantenna. Experimental results show that 20% of the photons are emitted into a very low numerical aperture (NA < 0.25), a 20-fold improvement over a free-standing quantum dot, and with a probability of more than 70% for a single photon emission. With an NA = 0.65 more than 35% of the single photon emission is collected. The single photon purity is limited only by emission from the metal, an obstacle that can be bypassed with careful design and fabrication. The concept presented here can be extended to many other types of quantum emitters. Such a device paves a promising route for a high purity, high efficiency, on-chip single photon source operating at room temperature.
Bibliographical noteFunding Information:
This work was supported in parts by the Einstein Foundation Berlin, by the U.S. Department of Energy: Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, the European Cooperation in Science and Technology through COST Action MP1302 Nanospectroscopy and by the Ministry of Science and Technology, Israel.
© 2016 American Chemical Society.
- colloidal nanocrystals
- nano-optical devices
- quantum dots
- single photon source