Shining a Light on Germanium-Vacancy Single Photon Emitters
We are happy to announce that the paper “Integration of germanium-vacancy single photon emitters arrays in diamond nanopillars” has been published in Februray 2025 on EPJ Quantum Technology Journal. This paper marks an important step forward in the SD-FBK development of diamond-based quantum technologies, and was achieved thanks to the work of the MNF and MTSD research units, who are working at the forefront of this field. The color-center-based diamond quantum platform was started a few years ago as part of the Q@TN project, and is now growing thanks to large-scale European projects. The recent EPJ Quantum Technology publication is the result of a collaboration between Fondazione Bruno Kessler (FBK), the University of Torino, the National Institute of Metrological Research (INRIM), and Qnami AG, a Swiss company in quantum sensing technologies. This partnership brought together the Micro-Nano Facility (MNF) and the Materials and Microsystems (MTSD) research units, focusing on the development of arrays of single-photon emitters integrated in diamond nanopillars to enhance photon extraction.
Nanopillars in diamond (courtesy of Qnami)
The novelty of this study was the integration of the quantum se elements in third-party devices: these emitters were precisely aligned with 300 nm diameter nanopillar waveguides, crafted through electron-beam lithography and plasma etching techniques. This accurate fabrication process achieved a remarkable 300 nm resolution in embedding Germanium-Vacancy (GeV) centers within nanostructures. As a result, a significant enhancement in photon collection efficiency was observed, leading to an overall increase in the emission intensity from the GeV centers. Moreover, this improvement contributed to an increase in the signal-to-noise ratio (SNR) by up to 8 times in pillar arrays containing varying numbers of GeV centers. Additionally, the fabrication process demonstrated a high yield of single-photon emission within the pillars, further confirming its effectiveness for quantum photonic applications.
The SD Center researchers involved in this activity have demonstrated expertise not only in the creation of colour centres in diamond substrates, but also in the use of advanced characterisation techniques based on Raman spectroscopy and photoluminescence (PL) measurements.This study is not only a promising step forward in understanding these phenomena, but also a demonstration of how research and industry partners can successfully collaborate to drive innovation in quantum technologies. In particular, the fabrication of large arrays of high-density, diffraction-limited single-photon emitters with micrometer spacing could pave the way for integrated photonic chips. These chips hold the potential for parallel quantum information processing and the generation of multiphoton Fock states, representing a significant advance in quantum technology applications.
Link to the paper
EPJ Quantum Technology (Springer open)
Authors of the Paper
Elisa Redolfi, Vanna Pugliese, Elia Scattolo, Alessandro Cian, Elena Missale, Felipe Favaro de Oliveira, Gediminas Seniutinas, Sviatoslav Ditalia Tchernij, Rossana Dell’Anna, Paolo Traina, Paolo Olivero, Damiano Giubertoni & Jacopo Forneris
About the author
Alessandro Cian, Research Scientist for the Fondazione Bruno Kessler and Science Ambassador for the SD Center.
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