Breakthrough in single-photon integration holds promise for quantum computing, cryptography

Phys.org  February 12, 2024 An international team of researchers (Israel, Germany, USA- Los Alamos National Laboratory) demonstrated an important step toward on-chip integration of single-photon sources at room temperature. Excellent photon directionality was achieved with a hybrid metal–dielectric bullseye antenna, while back-excitation was permitted by placement of the emitter in a subwavelength hole positioned at its center. The design enabled a direct back-excitation and very efficient front coupling of emission either to a low numerical aperture (NA) optics or directly to an optical fiber. They fabricated devices containing either a colloidal quantum dot or a nanodiamond containing silicon-vacancy centers. Both […]

Coupling of electron-hole pairs

Nanowerk  September 5, 2022 In two-layered molybdenum disulfide, excitation with light produces two different types of electron-hole pairs: intralayer pairs, in which the electron and hole are localized in the same layer of the material, and interlayer pairs, whose hole and electron are in different layers and are therefore spatially separate from one another. The intralayer pairs interact strongly with light. The interlayer excitons are much dimmer but can be shifted to different energies and therefore allow researchers to adjust the absorbed wavelength. They exhibit very strong, nonlinear interactions with one another which play an essential role in many of […]