Credit: Hebrew University of Jerusalem
A recent study revealed a significant advance toward on-chip integration of single-photon sources at room temperature. This achievement represents a significant advance in the field of quantum photonics and holds promise for various applications, including quantum computing, cryptography, and sensing.
The key innovation lies in the implementation of a hybrid metal-dielectric antenna, which provides exceptional photonic directionality. This new antenna design allows for efficient feedback excitation of photons by placing the transmitter in a sub-wavelength hole positioned in the center of the antenna. This configuration allows both direct feedback excitation and very efficient front-end coupling of the emission to low numerical aperture optics or optical fibers.
The study demonstrates the versatility of this concept by fabricating devices containing either colloidal quantum dots or nanodiamonds containing vacant silicon centers, both of which are excellent single photon emitters, even at room temperature. These emitters were precisely positioned using two distinct nanopositioning methods.
Remarkably, both types of back-excited devices exhibited front-end collection efficiencies of approximately 70% at numerical apertures as low as 0.5. This means that one can use very simple and compact optical elements and still collect most of the photons in the desired channel or accurately send the emitted photons into a nearby optical fiber without the need for additional coupling optics.
This is a key ingredient for integrating quantum light sources into real quantum systems. This streamlined process promises to simplify future integration efforts and accelerate the realization of practical quantum photonic devices.
The research paper titled “Room-Temperature Fiber-Coupled Single-Photon Sources based on Colloidal Quantum Dots and SiV Centers in Back-Excited Nanoantennas” is published in Nano letters.
The work was led by Boaz Lubotzky during his Ph.D. research, with Professor Ronen Rapaport of the Racah Institute of Physics at the Hebrew University of Jerusalem, in collaboration with teams from Los Alamos National Laboratory and the University of Ulm in Germany.
Lubotzky commented on the significance of this achievement, saying: “By overcoming key challenges associated with on-chip integration of single photon sources, we have opened up exciting new possibilities for the development of advanced quantum technologies. »
The successful integration of single-photon sources on tiny chips at room temperature, achieved through the innovative use of a metal-dielectric hybrid antenna, has immediate applications for advancing quantum cryptography for secure communication, improving sensing technologies and streamline the integration process for practical quantum photonic devices.
The study results open the door to commercial applications and new product development in the growing field of quantum technologies.
More information:
Boaz Lubotzky et al, Room temperature fiber-coupled single photon sources based on colloidal quantum dots and SiV centers in back-excited nanoantennas, Nano letters (2024). DOI: 10.1021/acs.nanolett.3c03672
Provided by the Hebrew University of Jerusalem
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