Category Physics

An illustration of topological surface states in bismuth iodide as seen by angle-resolved photoemission spectroscopy. Credit: Oleg Yazyev (EPFL)

Topological insulators are materials that let electric current flow across their surface while keeping it from passing it through their bulk. This exotic property makes topological insulators very promising for electricity with less energy loss, spintronics, and perhaps even quantum computing. EPFL scientists have now identified a new class of topological insulators, and have discovered its first representative material, which could propel topological insulators into applications.

By theoretically testing potential candidates from the database of previously described materials, Oleg Yazyev EPFL team has identified a material, “crystalline phase” o...

(Left) Silicon wires with match heads and (right) light absorption profile of a single match-head wire at 587 nm absorption. Credit: Image courtesy of the Center for Integrated Nanotechnologies

Crystal growth on a nano/microscale level produces “match-head”-like, 3D structures that enhance light absorption and photovoltaic efficiency. This is the first large structure grown on a nanowire tip and it creates a completely new architecture for harnessing energy. Match-head semiconductor nanowires focus incident light for greater overall efficiency. The match heads are naturally formed during the wire-growth process, which can be applied to various materials and structures for photonic and optoelectronic devices.

Enhanced light absorption and efficient, photogenerated carrier collection are...

The A-form of DNA between two electrodes. Credit: Image courtesy of University of California – Davis

Conductance of DNA can be modulated by controlling its structure, thus opening up the possibility of DNA’s future use as an electromechanical switch for nanoscale computing. Although DNA is commonly known for its biological role as the molecule of life, it has recently garnered significant interest for use as a nanoscale material for a wide-variety of applications.

Changing the structure of the DNA double helix by modifying its environment allows the conductance to be reversibly controlled. This ability to structurally modulate the charge transport properties may enable the design of unique nanodevices based on DNA...

The study provides insights into evolutionary distribution of different types of existing protein complexes. The table provides a valuable tool for biotechnology and the engineering of novel complexes.

Almost every biological process depends on proteins interacting and assembling into complexes in a specific way, and many diseases are associated with problems in complex assembly. The principles underpinning this organisation are not yet fully understood, but by defining the fundamental steps in the evolution of protein complexes, the new ‘periodic table’ presents a systematic, ordered view on protein assembly, providing a visual tool for understanding biological function.

“Evolution has given rise to a huge variety of protein complexes, and it can seem a bit chaotic,” explains Joe Marsh...