Physics Today Daily Edition
MIT Technology Review: Silicene is a single-layer molecule made from silicon. Like its carbon-based cousin graphene, silicene has unusual properties that make it potentially very useful in electronics. Unlike graphene, silicene does not occur naturally and is much less chemically and structurally stable in a two-dimensional form. Now, Deji Akinwande of the University of Texas at Austin and his colleagues have developed a method of growing the material that helps strengthen the molecule. They used the silicene as the base for contacts for a transistor, and the setup was stable in a vacuum. Although far from being commercially practical, the demonstration represents a significant proof of concept for the development of silicene-based electronics.
Nature: Last week it was confirmed that the apparent ripples in the cosmic microwave background (CMB) radiation detected by BICEP2 were almost entirely due to intergalactic dust. Nevertheless, researchers have been continuing to develop more sensitive experiments to look even more closely at the CMB. A set of five telescopes, each individually as sensitive as BICEP2, called the Keck Array, is undergoing upgrades that will allow it to measure both the dust and the CMB in the same patch of sky. BICEP3, the successor to BICEP2, will match the Keck Array's sensitivity in a single telescope. The biggest difference from its predecessor is that BICEP3 will be examining the sky at the lower 95 GHz frequency, where it is believed dust will cause less interference on potential signals. Both BICEP3 and the Keck Array will be looking at the same area of sky as BICEP2 did, but two other projects are already looking at wider areas of the sky and could potentially find a signal before either BICEP3 or the Keck Array is operational.
New Scientist: If you take a strip of paper and give it a half twist and tape the ends together, the result is the one-sided loop known as a Möbius strip. Now, Peter Banzer of the Max Planck Institute for the Science of Light in Erlangen, Germany, and his colleagues have demonstrated a similar effect using light. In 2005 it was predicted that light's polarization could become twisted like a Möbius strip. Banzer and his team achieved the effect by scattering two polarized beams off gold nanoparticles in such a way that the beams interfered with each other. The resulting light had polarizations with either three or five twists. The ability to twist polarized light could reveal details about light's 3D structure, which could lead to uses in biomedical imaging and particle manipulation.
Nature: On 29 January, the Nuclear Regulatory Commission (NRC) released the final two volumes of its technical analysis of the Department of Energy's proposal to use Yucca Mountain in Nevada as a nuclear waste repository. Although the report indicates that DOE's plan is sound, the NRC does not recommend going ahead with the construction. President Obama abandoned the project five years ago. Yet a federal court ruled that the NRC had to continue the study while it still had funds to do so. Even if Congress were to provide more funding for the next step (a further analysis of ecological impacts), the local governments in Nevada are openly resistant to selling the land to the federal government. Without that land, construction cannot begin.