Diamond as a Platform for Integrated Quantum Photonics

Abstract

Integrated quantum photonics enables the generation, manipulation, and detection of quantum states of light in miniaturized waveguide circuits. Implementation of these three operations in a single integrated platform is a crucial step toward a fully scalable approach to quantum photonic technologies. In this context, diamond has emerged as a particularly promising material as it naturally combines a large transparency range for the fabrication of low‐loss photonic circuits, and a variety of optically active defects for the realization of efficient single‐photon emitters. Furthermore, its high Young's modulus makes it ideal for the implementation of tunable optomechanical devices for active quantum state manipulation. This review reports recent progress on the realization of the main components required for a diamond‐based integrated quantum photonic architecture: single‐photon emitters, static and actively tunable waveguide circuits, and, as a last building block, integrated superconducting single‐photon detectors.

Building Blocks for Quantum Network Based on Group‐IV Split‐Vacancy Centers in Diamond

“…Recently, coupling of single ion‐implantation‐generated GeV − center to various photonic structures has also been demonstrated, for example, nanoscale diamond waveguide, nanodiamond‐embedded surface plasmonic waveguide, and micro‐disk or micro‐ring cavities fabricated from the overgrown diamond membranes . Thanks to the better overlap of defect's cross‐section with the waveguide mode, the quantum efficiency of GeV − center in waveguide is estimated to be no less than 40%, which is one order of magnitude larger than those found in micro‐diamond . The high quantum efficiency promises device with significant higher cooperativity, which is a critical factor in realizing deterministic single atom–photon interaction and deterministic two‐photon gates …”

Tunable Open‐Access Microcavities for Solid‐State Quantum Photonics and Polaritonics

“…Solid‐state single‐photon emitters, including QDs, vacancy color centers, single molecules, provide atomic‐like two‐level systems by the nanoscale confinement of charge carriers that enable significant applications for on‐chip quantum information processing . The investigation of cavity quantum electrodynamics (CQED) by integrating single‐photon emitters in microcavities allows tailoring the light–matter interaction, leading to enhanced spontaneous emission rate via the Purcell effect, higher photon collection efficiency, better photon purity and indistinguishability, as well as photon–spin interfaces .…”

“…The nitrogen vacancy (NV) centers in diamonds have been intensively investigated for quantum information processing due to its long spin coherence time and robust single‐photon emission . Microcavities are commonly used as the main platform for embedding the NV center for high generation rate and collection efficiency of indistinguishable single photons, as well as for enhancing the zero‐phonon‐line (ZPL) emission of the NV center at room temperature.…”

“…The nitrogen vacancy (NV) centers in diamonds have been intensively investigated for quantum information processing due to its long spin coherence time and robust single-photon emission. [134,151,152] Microcavities are commonly used as the main platform for embedding the NV center for high generation rate and collection efficiency of indistinguishable single photons, as well as for enhancing the zero-phonon-line (ZPL) emission of the NV center at room temperature. The integration of NV centers has been successfully demonstrated in WGM and 2D photonic crystal (PhC) cavities, [153][154][155] however, it remains challeng-ing to fabricate a NV center-embedded microcavity with both small mode volume and highly directional emission.…”

Quantum Technologies are (in) QUTE

“…Key areas include quantumbased communication, computation, control, engineering, information, metrology, optics, sensing and simulation, as well as adjacent areas such as nanophotonics, quasiparticle excitations, topological materials, superconductors, microand nano-electromechanical systems, ultracold atoms and others. The first three issues published in 2018 already provided a glimpse of our intended broad topical spectrum, with Reviews on continuous-variable quantum key distribution, [3] non-equilibrium Bose-Einstein-like condensation [4] and integrated quantum photonics based on diamond, [5] accompanied by original research contributions as Communications or Full Papers. Now, what do we have in store for the New Year: The present issue features, for example, a Review on topological insulators and semimetals for magnetoresistive sensors [6] and a Progress…”