(Funded by the U.S. Department of Defense, the U.S. Department of Energy and the U.S. National Science Foundation)
Researchers at Caltech have developed an on-chip transducer that converts microwave photons to optical photons. The device involves a tiny silicon beam that vibrates at 5 gigahertz and couples to a microwave resonator – essentially a nanoscale box in which photons bounce around, also at 5 GHz. Using a technique called electrostatic actuation, a microwave photon is converted within that box to a mechanical vibration of the beam, and that mechanical oscillation, with the help of laser light, gets converted by the resonator into an optical photon. Such a conversion could enable the construction of large-scale distributed superconducting quantum computers.

(Funded by the U.S. Department of Energy and the National Institutes of Health)
Researchers at Cornell University have, for the first time, identified what happens when bacteria receive electrons from quantum dots. Using fluorescence lifetime imaging microscopy with two-photon excitation on a quantum dot and bacteria, the researchers identified a distinct halo surrounding the bacteria, which suggested the charge transfer was receiving some peripheral assistance. It turned out that an electron could either move directly from the quantum dot to the bacterium or be transferred from the bacterium via shuttle molecules. Photosynthetic biohybrids of this sort could potentially convert carbon dioxide into value-added chemical products, such as bioplastics and biofuels, and control other microbial processes.

(Funded by the U.S. Department of Defense and the U.S. Department of Energy)
Researchers from the Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab); the University of California, Berkeley; and Northwestern University have developed a way to engineer pseudo-bonds in materials. Instead of forming chemical bonds – which is what makes epoxies and other composites tough – the chains of molecules entangle in a way that is fully reversible. The researchers attached polystyrene chains to 100-nanometers-diameter silica particles to create “hairy particles.” These hairy particles self-assembled into a crystal-like structure, and the space available to each polystyrene chain depended on its position in the structure. While some chains became rigid under confinement, others ultimately disentangled and stretched. The result was a strong, tough, thin-film material, held firmly together by pseudo bonds of tangled polystyrene chains. The research was conducted, in part, at the Molecular Foundry, a DOE Office of Science user facility at Berkeley Lab.

(Funded by the U.S. Department of Defense and the U.S. Department of Energy)
Scientists from the U.S. Department of Energy’s Berkeley National Laboratory; the University of California, Berkeley; and Adamas Nanotechnologies Inc. in Raleigh, NC, have encased nanodiamonds – diamonds that are less than 100 nanometers in size – in tiny moving droplets of water to improve quantum sensing, a technology that uses quantum mechanics to measure physical quantities with high precision. As the droplets flowed past a laser and were hit by microwaves, the nanodiamonds gave off light. The amount of light in the presence of a microwave field was related to the materials around the nanodiamond, letting scientists determine whether a chemical of interest was nearby.

(Funded by the U.S. Department of Energy and the U.S. National Science Foundation)
Researchers from the U.S. Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL), Purdue University, and the University of Illinois Urbana−Champaign have used a nanoscale quantum sensor to measure spin fluctuations near a phase transition in a magnetic thin film. Thin films with magnetic properties at room temperature are essential for data storage, sensors and electronic devices because their magnetic properties can be precisely controlled and manipulated. The researchers used a specialized instrument called a scanning nitrogen-vacancy center microscope at the Center for Nanophase Materials Sciences, a DOE Office of Science user facility at ORNL. A nitrogen-vacancy center is an atomic-scale defect in diamond in which a nitrogen atom takes the place of a carbon atom, and a neighboring carbon atom is missing, creating a special configuration of quantum spin states.