Lifeboat Foundation

Researchers from PSI’s Spectroscopy of Quantum Materials group together with scientists from Beijing Normal University have solved a puzzle at the forefront of research into iron-based superconductors: the origin of FeSe’s electronic nematicity. Using Resonant inelastic X-ray scattering (RIXS) at the Swiss Light Source (SLS), they discovered that, surprisingly, this electronic phenomenon is primarily spin driven.

Electronic nematicity is believed to be an important ingredient in high-temperature superconductivity, but whether it helps or hinders it is still unknown.

Their findings are published in Nature Physics (“Spin-excitation anisotropy in the nematic state of detwinned FeSe”).

The traditional trial-and-error method in material research cannot meet the growing demand of various high performance materials, so developing a new effective paradigm of material science is extremely urgent. A study led by Dr. Xiao-Ming Jiang and Prof. Guo-Cong Guo (Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences) proposes a new research paradigm for material studies based on the “functional motif” concept.

Functional motif was defined as the critical microstructure units (e.g., constituent components and building blocks) that play a decisive role in generating certain material functions. These units could not be replaced with other structure units without losing or significantly suppressing the relevant functions. The functional motif paradigm starts with the main aspects of microscopic structures and the properties of materials. On the basis of this understanding, the functional motifs governing the material properties can be extracted and the quantitative relationships between them can be investigated, and the results could be further developed as the “functional motif theory.” The latter should be useful as a guideline for creating new materials and as a tool for predicting the physicochemical properties of materials.

The properties of materials are determined by their functional motifs and how they are arranged in the materials, with the latter determining the quantitative structure–property relationships. Uncovering the functional motifs and their arrangements is crucial in understanding the properties of materials, and the functional motif exploration enables the rational design of new materials with desired properties.

French manufacturer used 100% recycled material, green energy.

For those of us worried the world somehow got trapped in the wrong timeline, relax — scientists are now saying there might actually be two realities.

Two researchers from the University of Maryland released their findings in a study earlier this month in the journal Physical Review Research. According to a university press release, though, a second reality isn’t exactly what they set out to find. While studying layers of graphene, made with hexagons of carbon, the found repeating patterns that changed the way electricity moves.

Based on their research, the pair think they accidentally found a clue that could explain some of our current reality’s mysteries. According to the university’s media arm, they realized that experiments on the electrical properties of stacked sheets of graphene produced results that looked like little universes and that the underlying causes could apply to other areas of physics. In stacks of graphene, electricity changes behavior when two sheets interact, so the two hypothesize that unique physics could similarly emerge from interacting layers elsewhere—perhaps across the entire universe.

Researchers have developed a new kind of logic gate, the fundamental building block from which computers are made. Depending on the kind of logic gate and its rules, two inputs of any combination of 0 and 1 result in an output of either a 1 or 0. A single chip used in creating electronic components like processors and memory modules can contain billions of logic gates.

The newly developed logic gate, which demonstrates the viability of “lightwave electronics,” works orders of magnitudes faster than traditional logic gates. Ordinary logic gates have an input processing delay on the order of nanoseconds, but the new logic gates process inputs in only femtoseconds, a million times shorter than nanoseconds.

The new gates comprise two gold electrodes connected with a graphene wire, which is then zapped with laser pulses, adjusting the pulse’s phase to produce outputs of either a one or a 0. The shortened processing time for the new logic gates means that computers built on the technology would have their processing speeds measured on Petahertz (PHz) scale compared to the current Gigahertz (GHz).

Supernovas might spell the end for the star they happen to, but they aren’t only destructive phenomena. When a star approaches the end of its life and runs out of fuel, it explodes in an enormous outpouring of energy, leaving behind a small, dense core that becomes a black hole or a neutron star. This explosion, though destructive on an epic scale, can also leave behind a beautiful remnant created by the explosion’s shock wave.

A image recently released by the Hubble Space Telescope team shows one such supernova remnant, called DEM L249. Captured by Hubble’s Wide Field Camera 3 instrument and located in the constellation of Mensa, this delicate structure is formed from dust and gas ejected outward from the star’s location by the force of the blast.

“This object — known as DEM L249 — is thought to have been created by a Type 1a supernova during the death throes of a white dwarf,” the Hubble scientists write. “While white dwarfs are usually stable, they can slowly accrue matter if they are part of a binary star system. This accretion of matter continues until the white dwarf reaches a critical mass and undergoes a catastrophic supernova explosion, ejecting a vast amount of material into space in the process.”

A new publication in Opto-Electronic Advances overviews dynamic metasurfaces and metadevices empowered by graphene.

Metasurfaces, artificial subwavelength structured interfaces, exhibit unprecedented capabilities to manipulate electromagnetic (EM) waves ranging from visible to terahertz and microwave frequencies.

In the past decade, static metasurfaces and metadevices have been researched extensively. Due to the passive nature of building blocks in general made of metals and/or dielectrics, however, their functionalities cannot be actively tuned in situ after fabrication, which seriously impedes their application scenarios such as varifocal lens, dynamic holography, and beam steering in LiDAR. Motivated by those significant requirements, scientists have struggled for years to improve the dynamical tunability of metasurfaces, and introducing active materials or components into the passive metasurfaces has been proposed as the first thought strategy.

Logic gates are the fundamental building blocks of computers, and researchers at the University of Rochester have now developed the fastest ones ever created. By zapping graphene and gold with laser pulses, the new logic gates are a million times faster than those in existing computers, demonstrating the viability of “lightwave electronics.”

Logic gates take two inputs, compare them, and then output a signal based on the result. They can, for example, output a 1 if both incoming signals are a 1 or a 0, or if either or neither of them is a 1, among other “rules.” Billions of individual logic gates are crammed into chips to create processors, memory and other electronic components.

More Stories

A team of researchers from China, Germany and the U.S. has developed a way to create a less fragile diamond. In their paper published in the journal Nature, the group describes their approach to creating a paracrystalline diamond and possible uses for it.

Prior research has shown that diamond is the hardest known material but it is also fragile—despite their hardness, diamonds can be easily cut or even smashed. This is because of their ordered atomic structure. Scientists have tried for years to synthesize diamonds that retain their hardness but are less fragile. The team has now come close to achieving that goal.

Currently, the way to create diamonds is to place a carbon-based material in a vice-like device where it is heated to very high temperatures while it is squeezed very hard. In this new effort, the researchers have used the same approach to create a less ordered type of diamond but have added a new twist—the carbon-based material was a batch of fullerenes, also known as buckyballs (carbon atoms arranged in a hollow spherical shape). They heated the material to between 900 and 1,300 °C at pressures of 27 to 30 gigapascals. Notably, the pressure exerted was much lower than is used to make commercial diamonds. During processing, the spheres were forced to collapse, and they formed into transparent paracrystalline diamonds which could be extracted at room temperature.