Category Physics

Physicists build stable diffraction structure in atomically thin graphene.
The quantum mechanical wave nature of matter is the basis for a number of modern technologies like high resolution electron microscopy, neutron-based studies on solid state materials or highly sensitive inertial sensors working with atoms. Prof. Markus Arndt group focused on how one can extend such technologies to large molecules and cluster.

In order to demonstrate the quantum mechanical nature of a massive object it has to be delocalized first >> achieved by Heisenberg’s uncertainty relation: If molecules are emitted from a point-like source, they start to ‘forget’ their position after a while and delocalize...

Artificial photosynthesis used to produce renewable molecular hydrogen for synthesizing carbon dioxide into methane. Credit: Berkeley Lab

Researchers using a bioinorganic hybrid approach to artificial photosynthesis have combined semiconducting nanowires with select microbes to create a system that produces renewable H2 and uses it to synthesize CO2 into methane, the primary constituent of natural gas.

“By generating renewable hydrogen and feeding it to microbes for the production of methane, we can now expect an electrical-to-chemical efficiency of better than 50% and a solar-to-chemical energy conversion efficiency of 10% if our system is coupled with state-of-art solar panel and electrolyzer.”

The concept in the 2 studies is essentially the same – a membrane of semiconductor nanowires t...

Ionization times (left axis) reconstructed using the ARM theory from offset angles (right axis) obtained numerically using TDSE calculations. Red circles are the numerically calculated offset angles, divided by the laser frequency, ?/?. Blue diamonds show the offset angles with the correction due to the substraction of the pulse envelope effect, ti0 = ?/?-|?tienv (?,ppeak)| . Green inverted triangles show the Coulomb correction to the ionization time evaluated at the peak of the photoelectron distribution, |?tiC (?,ppeak|. Orange triangles show the ionization times we obtain by applying the reconstruction procedure defined by equation (4) in the paper. In terms of the figure, this is simply the result of subtracting the green curve from the blue curve. Credit: (c) MBI

How long does it ta...

From the spinning disc of a computer’s hard drive to varying current in a transformer, many technological devices work by merging electricity and magnetism. Enter multiferroics, which combine 2 or more primary ferroic properties. Northwestern University’s James Rondinelli and his research team are interested in combining ferromagnetism and ferroelectricity, which rarely coexist in one material at room temperature.

In order for ferroelectricity to exist, the material must be insulating. So nearly every approach to date has focused on searching for multiferroics in insulating magnetic oxides. Rondinelli’s team started with a different approach...