title: Highly Directional Room-Temperature Single Photon Device.
abstract: 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.
authors.affiliation: Applied Physics Department, The Hebrew University of Jerusalem , Jerusalem 9190401, Israel.
authors.forename: Nitzan
authors.initials: N
authors.lastname: Livneh
authors.affiliation: Racah Institute for Physics, The Hebrew University of Jerusalem , Jerusalem 9190401, Israel.
authors.forename: Moshe G
authors.initials: MG
authors.lastname: Harats
authors.affiliation: Racah Institute for Physics, The Hebrew University of Jerusalem , Jerusalem 9190401, Israel.
authors.forename: Daniel
authors.initials: D
authors.lastname: Istrati
authors.affiliation: Racah Institute for Physics, The Hebrew University of Jerusalem , Jerusalem 9190401, Israel.
authors.forename: Hagai S
authors.initials: HS
authors.lastname: Eisenberg
authors.affiliation: Applied Physics Department, The Hebrew University of Jerusalem , Jerusalem 9190401, Israel.|Racah Institute for Physics, The Hebrew University of Jerusalem , Jerusalem 9190401, Israel.
authors.forename: Ronen
authors.initials: R
authors.lastname: Rapaport
keywords: colloidal nanocrystals; nano-optical devices; nanoantenna; plasmonics; quantum dots; single photon source