In certain materials, light waves can change their direction of polarization. Credit: TU Wien

The ‘quantized magneto-electric effect’ has been demonstrated for the first time in topological insulators at TU Wien, which is set to open up new and highly accurate methods of measurement. A light wave sent through empty space always oscillates in the same direction. However, certain materials can be used to rotate the direction in which the light is oscillating in a magnetic field, ie ‘magneto-optical’ effect. Rather than switching the direction of the light wave continually,’topological insulators’ do so in quantum steps in clearly defined portions. The extent of these quantum steps depends solely on fundamental physical parameters, such as the fine-structure constant...

1. Nanoporous nickel cathodes for lithium oxygen batteries are ultralight, shown here balanced on flower stamens.
Credit: American Chemical Society
2. Nanoengineered Ultralight and Robust All-Metal Cathode for High-Capacity, Stable Lithium–Oxygen Batteries

Lithium-oxygen systems could someday outperform today’s lithium-ion batteries because of their potential for high energy density. However, a number of important issues, such as their poor electrochemical stability must be addressed before these systems can successfully compete with current rechargeable batteries. Now, in ACS Central Sci

ence, researchers report a new type of cathode, which could make lithium-oxygen batteries a practical option.

Xin-Bo Zhang and colleagues note that most of the problems associated with lithium-oxygen batt...

This is the ASKAP telescope in Western Australia. Credit: CSIRO

A CSIRO telescope in W. Australia has found its first ‘fast radio burst’ from space after less than 4 days of searching. The discovery came so quickly that the telescope, the Australian Square Kilometre Array Pathfinder (ASKAP) near Geraldton in Western Australia, looks set to become a world champion in this fiercely competitive area of astronomy. The new fast radio burst finding was published in the Astrophysical Journal Letters.

‘Fast radio bursts’ or FRBs are short, sharp spikes of radio waves lasting a few milliseconds. They appear to come from powerful events billions of light-years away but their cause is still a mystery. The first was discovered in 2007 and only 2 dozen have been found since...

1.Evolution of the magnetic field in two simulations of the formation of active solar regions. Top row: non-eruptive scenario where the configuration remains stable. Bottom row: eruptive scenario.
Credit: © E.Pariat, figure adapted from Pariat & al, A&A 2017
2. Time evolution of the value of a quantity based on magnetic helicity, for the various numerical simulations tested. This predictive quantity has high values before the eruption in the eruptive simulations (red, orange and yellow curves) and low values in the non-eruptive cases (black, violet, blue and cyan curves).
3. Artist’s impression of a solar flare and the twisted magnetic field that carries away the ejected solar material.

The emerging discipline of space meteorology aims to reliably predict solar flares so that we may better g...