Imagine a world where light, instead of merely bouncing off surfaces or passing through transparent materials, is controlled in a completely new and unexpected way. Scientists have recently taken a major step in this direction by discovering what is called a “photonic axion insulator.” While this term might sound complicated, the underlying idea is both […]
A team of researchers has experimentally demonstrated a quantum tornado for the first time by refining an established method. In the quantum semimetal tantalum arsenide (TaAs), electrons in momentum space behave like a swirling vortex. This quantum phenomenon was first predicted eight years ago. Scientists have long known that electrons can form vortices in quantum […]
In a recent study, a team of researchers explores the intriguing electronic behaviours that emerge when two distinct forms of carbon-based materials—nanoporous graphene (NPG) and graphene—are layered together with a twist between them. Graphene is a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice, renowned for its exceptional electrical conductivity, mechanical strength […]
Two-dimensional (2D) materials have become a centrepiece of modern materials science, captivating researchers with their electronic, mechanical, and optical properties. Since Geim and Novoselov discovered the exfoliation technique in 2004, thousands of 2D materials have been discovered, synthesised, or predicted. In particular, anisotropic 2D materials display direction-dependent characteristics, promising cutting-edge applications in flexible electronics and […]
In the world of nanophotonics, the ability to control light with precision at the nanoscale is a game-changing goal. Recent advancements in materials science have opened up new pathways for achieving this, particularly through the use of van der Waals (vdW) crystals. These ultra-thin materials, composed of layers of atoms held together by weak van […]
Scientists seeking better methods for controlling the quantum interactions between light and matter demonstrated a novel way to use light to give electrons a spinning kick. The results of their experiment show that a light beam can reliably transfer orbital angular momentum to itinerant electrons in graphene. Having tight control over the way that light […]
In certain materials, when we apply an electric field (it could be that of light) that vibrates at a certain frequency, it can create a direct current, a steady flow of electrical charge. This current is special because its strength depends on the square of the electric field’s strength. This phenomenon is called “shift current.” […]
A gauge theory is any number of quantum field theories put forward to explain fundamental interactions. In these theories the interactions between particles can be explained by the exchange of particles such as gluons, photons, and W and Z bosons. A gauge theory involves a symmetry group for the fields and potentials (the gauge group) […]
Topological insulators are materials with special universal properties, which are protected against perturbations. Such properties are theoretically described by topology, a branch of mathematics concerned with the properties of geometrical objects that are unchanged by continuous deformations. Concretely, topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have […]
A diode is an electronic device with two electrodes. In the obsolescent thermionic diode a heated cathode emits electrons, which flow across the intervening vacuum to the anode when a positive potential is applied to it. The device permits flow of current in one direction only as a negative potential applied to the anode repels […]