News by Subject Chemistry & Physics

The group of Prof. Dr. Matthias Karg at the Institute of Physical Chemistry at Heinrich Heine University Duesseldorf (HHU) in Germany is creating ultra-thin, highly ordered layers of spherical hydrogel beads that encapsulate gold or silver particles. These structures are of interest for applications in optoelectronics -- light-based information and communication technology -- and nanophotonics. The researchers have recently published findings on a significant step in the direction of 'plasmonic nanolasers' in the journal ACS Applied Materials & Interfaces.

A multidisciplinary team has provided new insight into underlying mechanisms controlling the precise size of cells. The researchers found that 'the adder,' a function that guides cells to grow by a fixed size from birth to division, is controlled by specific proteins that accumulate to a threshold.

Physicists have demonstrated a new way to obtain the essential details of an isolated quantum system through direct observation. The method gives information about the likelihood of finding atoms at specific locations in the system with unprecedented spatial resolution far better than an optical microscope can provide. With this technique, scientists can obtain details on a scale of tens of nanometers -- smaller than the width of a virus.

Machine learning can be used to predict the properties of a group of materials which, according to some, could be as important to the 21st century as plastics were to the 20th.

Solar cells made of perovskite hold much promise for the future of solar energy. However, the material degrades quickly, severely limiting its efficiency and stability over time. Researchers from Eindhoven University of Technology, energy research institute DIFFER, Peking University and University of Twente have discovered that adding a small amount of fluoride to the perovskite leaves a protective layer, increasing stability of the materials and the solar cells significantly.

Strongly correlated materials can change their resistivity from infinity to zero with minute changes in conditions. Now, researchers have fabricated a flexible organic 'correlated' transistor that makes it possible to control the effective pressure and doping level by bending the substrate and changing the gate voltage, respectively. This device allows researchers to switch superconductivity on and off by using appropriate combinations of the two parameters, in a way that could lead to future quantum simulators.

The topological Hall effect (THE) is the Hall response to an emergent magnetic field, a manifestation of the skyrmion Berry-phase. As the magnitude of THE in magnetic multilayers is an open question, it is imperative to develop comprehensive understanding of skyrmions and other chiral textures, and their electrical fingerprint.

Graphene is an extraordinary material consisting of pure carbon just a single atomic layer thick. It is extremely stable, strong and conductive. In electronics, however, graphene has crucial disadvantages. It cannot be used as a semiconductor, since it has no bandgap. Now researchers from Göttingen and Pasadena have produced an "atomic scale movie" showing how hydrogen atoms can chemically bind to graphene to produce a bandgap in one of the fastest reactions ever studied. (Science 25.4.2019)