Scientific Results

Exploring ultrafast single-photon emission of silicon-vacancy color centers in diamond nano-membranes coupled with gold nano-cones

Year: 2019

Authors: Kambalathmana H., Flatae AM., Lagomarsino S., Galal H., Tantussi F., Messina GC., Worner E., Wild C., Gelli N., Sciortino S., Giuntini L., De Angelis F., Agio M.

Autors Affiliation: Univ Siegen, Lab Nanoopt & C, D-57072 Siegen, Germany; Ist Nazl Fis Nucl, Sez Firenze, I-50019 Sesto Fiorentino, Italy; Ist Italiano Tecnol, I-16163 Genoa, Italy; Diamond Mat GmbH, D-79108 Freiburg, Germany; Univ Florence, Dept Phys & Astron, I-50019 Sesto Fiorentino, Italy; CNR, CNR, Natl Inst Opt INO, I-50125 Florence, Italy

Abstract: Silicon-vacancy (SiV) color centers in diamond offer novel possibilities to probe light-matter interaction in nano-quantum optics and provide a scalable quantum system suitable for single-photon emission. However, their effective count-rate is still limited by non-radiative decay channels, radiation at wide angles and total internal reflection at the diamond interface. Recently optical antennas have been utilized in order to modify light-matter interaction at the nanoscale. Acting as resonators, they are able to increase the spontaneous emission rate of quantum emitters by several orders of magnitude in a broad spectral range. Because coupling a quantum emitter to a nano-antenna requires close proximity between the two systems, we implant Si ions on very thin diamond membranes that provide the required dimension for near-field interaction in a controlled manner and investigate the optical properties of SiV color centers in such diamond membranes. We consider gold nano-cones as nano-antennas, fabricated by focused electron beam induced deposition (EBID), followed by sputtering and focused ion beam (FIB) milling. The finite-difference time-domain (FDTD) calculations show that gold nano-cones can provide more than four orders of magnitude enhancement in the Purcell factor with an antenna efficiency (AE) of 80%.

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KeyWords: Diamond nano-membranes; silicon vacancy color centers; nano-cone; Purcell enhancement; optical nano-antenna; hybrid quantum system