February 15, 2024 – A significant advancement in on-chip integration of single-photon sources at room temperature by Hebrew University of Jerusalem researchers holds promise for various applications including quantum computing, cryptography, and sensing.

The recent study, published in Nanoletters by Boaz Lubotzky during his Ph.D. research, along with Prof. Ronen Rapaport from the Hebrew University Racah Institute of Physics, was done in collaboration with teams from Los Alamos National Laboratory (LANL) and Ulm University in Germany.

The key innovation discussed in the study is the implementation of a hybrid metal-dielectric bullseye antenna, which delivers exceptional photon directionality. The antenna’s unique structure allows photons to be efficiently coupled directly into an optical fiber.

The study demonstrates the versatility of this concept by fabricating devices containing either colloidal quantum dots or nanodiamonds containing room-temperature single-photon emitters. Using simple and compact optical elements, most of the photons can be collected into the preferred channel. Additionally, the emitted photons can be sent into a nearby optical fiber without the need for any additional coupling optics, a key factor in the integration of quantum light sources into actual quantum systems.

Photon Credit: Swati Foujdar

“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,” says Lubotzky. “The study’s findings open doors for commercial applications and the development of new products in the burgeoning field of quantum technologies, advancing quantum cryptography for secure communication, improving sensing technologies, and streamlining the integration process for practical quantum photonic devices.”

The study, titled “Room-Temperature Fiber-Coupled Single-Photon Sources based on Colloidal Quantum Dots and SiV Centers in Back-Excited Nanoantennas” can be found here.

Boaz Lubotzky1, Alexander Nazarov1,2, Hamza Abudayyeh1, Lukas Antoniuk3, Niklas Lettner3,4, Viatcheslav Agafonov5, Anastasia V. Bennett6, Somak Majumder6, Vigneshwaran Chandrasekaran6, Eric G. Bowes6, Han Htoon6, Jennifer A. Hollingsworth6, Alexander Kubanek3,4, and Ronen Rapaport1,2


  1. Racah Institute of Physics, The Hebrew University of Jerusalem
  2. The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem
  3. Institute for Quantum Optics, University of Ulm
  4. Center for Integrated Quantum Science and Technology (IQst), Ulm University
  5. GREMAN, UMR 7347 CNRS, INSA-CVL, Tours University
  6. Materials Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory