Purcell-enhanced emission from individual SiV⁻ center in nanodiamonds coupled to a Si₃N₄-based, photonic crystal cavity

Abstract

<jats:title>Abstract</jats:title><jats:p>Hybrid quantum photonics combines classical photonics with quantum emitters in a postprocessing step. It facilitates to link ideal quantum light sources to optimized photonic platforms. Optical cavities enable to harness the Purcell-effect boosting the device efficiency. Here, we postprocess a free-standing, crossed-waveguide photonic crystal cavity based on Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub> with SiV<jats:sup>−</jats:sup> center in nanodiamonds. We develop a routine that optimizes the overlap with the cavity electric field utilizing atomic force microscope (AFM) nanomanipulation to attain control of spatial and dipole alignment. Temperature tuning further gives access to the spectral emitter-cavity overlap. After a few optimization cycles, we resolve the fine-structure of individual SiV<jats:sup>−</jats:sup> centers and achieve a Purcell enhancement of more than 4 on individual optical transitions, meaning that four out of five spontaneously emitted photons are channeled into the photonic device. Our work opens up new avenues to construct efficient quantum photonic devices.</jats:p>

Hybrid Quantum Photonics Based on Artificial Atoms Placed Inside One Hole of a Photonic Crystal Cavity

“…Our photonic interface is based on a freestanding onedimensional PCC built out of Si 3 N 4 [14,24]. The cavity is formed by two bragg mirrors with N=43 holes separated from each other with a period of a = 265 nm, while the cavity defect is introduced between the two bragg mirrors with a distance of 232 nm.…”

“…There-fore, we use a hybrid quantum photonics approach that allows us to integrate atomic systems in complex, on-chip photonic circuits [11]. Hybridization to date often relies on evanescent coupling [12][13][14][15] with coupling rates limited by the exponential decay of the electric field. Our approach is based on a long-standing goal in cQED, namely to position an atom in the electric field maximum of a photonic crystal cavity (PCC).…”

Prolonged orbital relaxation by locally modified phonon density of states for SiV$^-$ center in nanodiamonds

“…Moreover, due to the NDs integration capability into photonic structures, passive photonic and phononic properties could be merged and leveraged to achieve coherent spin-photon control [24].…”

Comparison of the semiclassical and quantum optical field dynamics in a pulse-excited optical cavity with a finite number of quantum emitters

“…Semiconductor quantum dots (QDs) in a microcavity are a prominent realization of such quantum light sources with a variety of different applications ranging from QD lasers [1,2] involving QDs in laterally extended cavities formed by Bragg mirrors down to single QE structures for applications in the field of quantum information technology [3]. Color centers of different types placed in a microcavity, such as nitrogen-vacancy [4][5][6][7] or silicon-vacancy centers [8,9] in diamond, defect states in hexagonal boron nitride [10,11], or organic molecules [12] constitute another class of QEs coupled to a single light mode, which are currently extensively studied. Increasing possibilities to create deterministic photon emitter structures, e.g., by strain-patterning of 2D semiconductors [13][14][15], by lithographic positioning of nanodiamonds [16] or by irradiation with a narrow helium beam [17] also pave the way for studying systems with well-defined finite numbers of photon emitters.…”