Germanium for Spintronics
Germanium is an attractive material for spintronics because it can sustain spin-polarized currents for long periods of time and it’s easily interfaced with silicon—the basis for most of today’s electronics. Germanium can also carry a spin-polarized current over nearly half a micrometer. There is a surprisingly large spin Hall effect in the semiconductor, an effect that can be used to efficiently convert an electrical current into a spin-polarized one.
Density-Functional Theory Gets Better
When it comes to computing the electronic properties of molecules and solids, density-functional theory (DFT) is often the method of choice. There is a new approach to finding the electronic potentials in the time-dependent extension of DFT that may lead to improving the theory’s approximations. There is a promising method to make DFT calculations of molecular energies more accurate.
The Many Facets of Graphene
Since Andre Geim and Konstantin Novoselov extracted graphene from graphite, researchers have explored the ins and outs of the wonder material. There is a method for producing free-standing graphene sheets with some of the highest electron mobilities of any inorganic semiconductor. Graphene can be folded into various structures that could be optimized to exhibit desired optical and electronic properties. Graphene, which is intrinsically nonmagnetic, can be made ferromagnetic by doping it with magnetic impurities, without disturbing its exceptional conductivity.
A Platinum Hit
Computers can sift through far more potential materials than a human could ever make in the lab. This high-throughput approach has been used to predict 28 new platinum-containing alloys, which could be useful for industrial applications like catalysis.
Engineering Orbital Occupancy in Transition-Metal Oxides
Transition-metal oxides exhibit superconductivity, ferroelectricity, or other remarkable properties depending on which of the orbitals of the transition-metal ions are occupied by electrons. A study demonstrating the ability to selectively populate a particular orbital state of one such oxide, a nickelate, by sandwiching a thin film of the material between different oxides.
Birth of the Weyl
Weyl states are some of the latest examples of states that can emerge in materials with topological character. We described the experimental discovery of Weyl states in a semimetal and in a photonic crystal.
Superconductivity Prediction Borne Out by Experiments
The track record for predicting that a certain material will superconduct is notoriously bad, but advances in computational materials science are beginning to change this trend. Computational electronic-structure calculations led to the discovery in 2013 of low-temperature superconductivity in iron tetraboride.
Helicoidal Magnetism Induces Giant Electrical Polarization
Multiferroic materials, in which magnetic order and electrical polarization are strongly coupled, could lead to devices that control charges through magnetic fields or spins through voltages. A record-breaking electrical polarization induced by helicoidal magnetic order in an oxide.