Why do avalanches start to slide? And what happens inside the “pile of snow?” If you ask yourself these questions, you are very close to a physical problem. This phenomenon not only occurs on mountain peaks and in snow masses, where it is rather uncontrolled—it is also studied in the laboratory at the microscopic level in materials with a disordered particle structure, for example in glasses, granular materials or foams.

Particles can “slide” in a similar way to avalanches, causing the structure to lose its stability and become deformable, even independently of a change in temperature. But what happens inside such a shaky structure?

Physicist Matthias Fuchs from the University of Konstanz and his colleagues Florian Vogel and Philipp Baumgärtel are researching these disordered solids. Two years ago, they solved an old puzzle about glass vibrations by revisiting a forgotten theory. “Now we have continued the project to answer the question of when an ‘irregular house of cards collapses.’ We want to find out when an amorphous solid loses its stability and starts to slide like a pile of sand,” says Fuchs.

A research group recently discovered the disappearance of nonreciprocal second harmonic generation (SHG) in MnPSe₃ when integrated into a two-dimensional (2D) antiferromagnetic MnPSe₃/graphene heterojunction.

The research, published in Nano Letters, highlights the role of interfacial magnon-plasmon coupling in this phenomenon.

2D van der Waals magnetic/non-magnetic heterojunctions hold significant promise for spintronic devices. Achieving these functionalities hinges on the interfacial proximity effect, a critical factor. However, detecting the proximity effect in 2D antiferromagnetic/non-magnetic heterojunctions presents considerable challenges, due to the small size and weak signals associated with these structures.

A new trick for illuminating the internal ordering within a special type of magnet could help engineers build better memory-storage devices. Developed by RIKEN physicists, this technique could make memory devices less corruptible.

The work is published in the journal Nature Communications.

Conventional hard disks are based on ferromagnets—materials in which the magnetic dipoles, or spins, associated with each atom all point in the same direction. This alignment gives the material a net magnetic field. Data is stored by creating different magnetization patterns across the material.

The Anderson transition is a phase transition that occurs in disordered systems, which entails a shift from a diffusive state (i.e., in which waves or particles are spread out) to a localized state, in which they are trapped in specific regions. This state was first studied by physicist Philip W. Anderson, who examined the arrangement of electrons in disordered solids, yet it was later found to also apply to the propagation of light and other waves.

Researchers at Missouri University of Science & Technology, Yale University, and Grenoble Alpes University in France recently set out to further explore the Anderson transition for light (i.e., electromagnetic waves) in 3D disordered systems.

Their paper, published in Physical Review Letters, outlines the simulation of light wave transport in an arrangement of perfect-electric-conducting (PEC) spheres, materials that reflect electromagnetic waves.