Category Physics

An illustration of the Migration Enhance Encapsulated Growth (MEEG) process to stabilize novel wide-bandgap two-dimensional nitride semiconductors that are not naturally occurring. MEEG is facilitated by defects in the graphene lattice that act as pathways for intercalation. When the gallium and nitrogen adatoms meet at the graphene/SiC interface, they chemically react to form two-dimensional gallium nitride. Credit: Z. Al Balushi and Stephen Weitzner, Penn State MatSE

A newly discovered method for making two-dimensional materials could lead to new and extraordinary properties, particularly in nitrides, say the Penn State materials scientists who discovered the process...

In the proposed experiment, two energy reservoirs (S and D) made of trapped ions transport energy quanta to each other by coupling to the spins in a quantum magnet placed between them. Credit: Alejandro Bermudez and Tobias Schaetz, New Journal of Physics. CC-BY-3.0

The first method to control transport of energy at the level of single energy quanta (which are mostly phonons) has been proposed. It’s theoretically possible to control the flow of single energy quanta through a quantum magnet using lasers with carefully controlled frequencies and intensities. If implemented, the method could allow researchers to explore quantum energy transport phenomena that are expected to be completely different than what is observed in macroscopic energy transport...

A short laser pulse travels through a diamond (black spheres) and excites electrons inside it. The strength of the excitation is measured using an attosecond ultraviolet pulse (violet). Credit: Matteo Lucchini, Copyright ETH Zurich

These insights are important for petahertz electronics of the future. Today’s electronic circuits already routinely work at frequencies of several gigahertz (a billion oscillations per second) up to terahertz (a thousand billion oscillations). Modern computers are as powerful as they are because tiny switches inside them steer electric currents in fractions of a billionth of a second...

An effective and low-cost solution for storing solar energy. Credit: © Infini Lab / 2016 EPFL

How can we store solar energy for period when the sun doesn’t shine? One solution is to convert it into hydrogen through water electrolysis. The idea is to use the electrical current produced by a solar panel to ‘split’ water molecules into hydrogen and oxygen. Clean hydrogen can then be stored away for future use to produce electricity on demand, or even as a fuel.

Even though different hydrogen-production technologies have given us promising results in the lab, they are still too unstable or expensive and need to be further developed to use on a commercial and large scale...