What if electricity and magnetism, usually considered as separate or even competing forces in materials, could actually work together in harmony?
Category: materials
Stronger Magnetic Fields Without Superconductors? Scientists Say Yes
Two German physicists have unveiled a compact magnet layout that outperforms the famed Halbach array, delivering stronger, more even magnetic fields without bulky superconductors.
Their 3D-printed ring stacks matched analytic predictions and could slash the cost of MRI machines while opening doors for levitation tech and particle accelerators.
Breakthrough in Magnetic Field Generation.
Coupled electrons and phonons may flow like water in 2D semiconductors
A condition long considered to be unfavorable to electrical conduction in semiconductor materials may actually be beneficial in 2D semiconductors, according to new findings by UC Santa Barbara researchers published in the journal Physical Review Letters.
Electron-phonon interactions—collisions between charge-carrying electrons and heat-carrying vibrations in the atomic lattice of the material—are considered the primary cause of electrons slowing down as they travel through semiconductor material. But according to UCSB mechanical engineers Bolin Liao and Yujie Quan, when electrons and phonons are considered as a single system, these interactions in atomically thin material prove to actually conserve total momentum and energy, and could have important implications for 2D semiconductor design.
“This is in sharp contrast to three-dimensional systems where you have a lot of momentum loss processes,” said Liao, who specializes in thermal and energy science.
Topological Twist for Phase Transitions
Contrary to conventional wisdom, so-called order parameters that distinguish symmetry-governed phases of matter can have topological structure.
From materials developing magnetization patterns to metals becoming superconductors, a wide range of phase transitions can be qualitatively described by a single framework known as Ginzburg-Landau theory [1, 2]. This framework generally assumes that a key quantity in its descriptions, called an order parameter, has trivial topology. But now, Canon Sun and Joseph Maciejko at the University of Alberta, Canada, have shown that order parameters can have hidden topological structure [3]. The researchers have developed an extension to Ginzburg-Landau theory that incorporates such hidden topology, revealing features absent from the original framework.
Symmetry constitutes a fundamental concept in physics. It appears in many guises but is especially important when studying how interactions of countless microscopic constituents give rise to macroscopic order in condensed-matter systems. For example, below a critical temperature, an ordinary magnet has a net magnetization because its spins all align in the same direction, breaking rotational symmetry. If the magnet is heated above that temperature, it loses its magnetization as its spins point in random directions, restoring rotational symmetry.
More pathways that previously thought can lead to optical topological insulators
The candidate pool for engineered materials that can help enable tomorrow’s cutting-edge optical technologies—such as lasers, detectors and imaging devices—is much deeper than previously believed.
That’s according to new research from the University of Michigan that examined a class of materials known as topological insulators. These materials have exciting and tunable properties when it comes to how they transmit energy and information.
“We see this as a step toward building a more versatile and powerful foundation for future photonic technologies,” said Xin Xie, a research fellow in the U-M Department of Physics and lead author of the recent study in the journal Physical Review X.
A new atomistic route to viscosity—even near the glass transition
We rarely think about how liquids flow—why honey is thick, water is thin or how molten plastic moves through machines. But for scientists and engineers, understanding and predicting the viscosity of materials, especially polymers, is essential.
Viscosity governs how substances deform and flow under stress, which in turn affects how they are processed, how they behave in industrial pipelines, in environmental settings, or in consumer products, and how they respond to changing temperatures.
Traditionally, to calculate the viscosity of a liquid or polymer melt based on molecular simulations on computers, people rely on a method called the Green–Kubo formalism. It works by tracking how internal stresses fluctuate and decay over time inside a simulated material at thermodynamic equilibrium.
High explosives in slow motion: Freezing molecules in place shows chemical reactions
Safe and effective high explosives are critical to Lawrence Livermore National Laboratory’s (LLNL) mission of stockpile stewardship. It is relatively simple to study the composition of such material before a detonation or examine the soot-like remnants afterward. But the chemistry in between, which dictates much of the detonation process, evades experimental interrogation as it passes by in a few nanoseconds or less.
In a study published in the Proceedings of the National Academy of Sciences, researchers from SLAC National Accelerator Laboratory and LLNL triggered a slow decomposition of a high explosive and measured the effects on the molecules within it. The work provides the proof of concept for a process that could be extended to examine ultra-fast dynamic chemistry during detonations and illuminates intermediate structures that have never been experimentally seen before.
At the Stanford Synchrotron Radiation Lightsource, the team used X-rays to both trigger the chemical reactions involved in decomposition and measure the results.
“Like Nothing Ever Seen Before”: Astronomers Discover a Colossal Milky Way Cloud Containing the Mass of 160,000 Suns
IN A NUTSHELL 🌌 Astronomers discovered a colossal molecular cloud named M4.7–0.8 in the Milky Way, weighing as much as 160,000 suns. 🔭 The Green Bank Telescope was instrumental in identifying this cloud located 23,000 light-years away, revealing its pivotal role in material transport. ⭐ Giant Molecular Clouds (GMCs) like M4.7–0.8 are critical for understanding