Single photon emission from isolated monolayer islands of InGaN  September 23, 2020 An international team of researchers (China, Japan, Germany) developed a novel type of quantum emitter formed from spatially separated monolayer islands of InGaN sandwiched in a GaN matrix. They first grew a planar structure of InGaN monolayer islands using molecular beam epitaxy, and then patterned the sample into pillars using nanoimprint lithography and inductively-coupled plasma reactive-ion etching. Detailed optical analysis of the emission properties of the isolated monolayer islands showed that the main emission line could be spectrally filtered to act as a bright, and fast single photon emitter at a wavelength of ~ 400 nm, […]

Scientists create new device to light up the way for quantum technologies  July 7, 2020 An international team of researchers (Ireland, UK) report theoretical statistics of 1- and 2-qubit (bipartite) systems, namely, photon antibunching and entanglement, of near-field excited quantum emitters. The sub-diffraction focusing of a plasmonic waveguide is shown to generate enough power over a sufficiently small region to strongly drive quantum emitters. This enables ultrafast single-photon emission as well as creates entangled states between two emitters when performing a controlled-NOT operation. The use of a movable plasmonic waveguide, in lieu of stationary nanostructures, allows high-speed rasterization between sets of qubits and enables spatially flexible data storage and quantum information […]

Light from stretchable sheets of atoms for quantum technologies

EurekAlert  April 16, 2020 Unlike other nanomaterials used as quantum light sources, such as diamond, silicon carbide or gallium nitride hexagonal boron nitride is not brittle and comes with the unique stretchable mechanical properties of a van der Waals crystal. However, their spectral inhomogeneity currently limits their potential applications. Researchers in Australia applied tensile strain to quantum emitters embedded in few‐layer hBN films. They observed both red and blue spectral shifts with tuning magnitudes up to 65 meV. Rotation of the optical dipole in response to strain suggested the presence of a second excited state. They developed a theoretical model […]