Category archives: Physics

Following the need for new and renewable sources of energy worldwide, fuel cells using electrocatalysts can be thought of as viable options. Catalyst materials modify and increase the rate of chemical reactions without itself undergoing any permanent change. An electrocatalyst is a catalyst that participates in electrochemical reactions and that functions at electrode surfaces or […]

When I first started writing about condensed matter science I found some difficulties with a few purely physical concepts, being myself a chemist by education. One of those was ‘polariton’. After some years of reading solid state physics papers and writing about them on a weekly basis, now is a familiar term, but I still […]

We tacitly assume that perfect order exists throughout crystalline materials on an atomic scale when we discuss crystals in general. However, such an idealized solid does not exist at all in nature. All of them contain large numbers of various defects or imperfections. As a matter of fact, many of the properties of materials are […]

Our core theory of fundamental physics, the Standard Model (SM), describes a vast range of phenomena precisely and very accurately. In that sense it is close to Nature’s last word. It presents, however, some shortcomings. For example, the SM contains three different forces and many independent fields. It is attractive to imagine that a deeper […]

For centuries, metals were employed in optical applications only as mirrors and gratings. New vistas opened up in the late 1970s and early 1980s with the discovery of surface-enhanced Raman scattering and the use of surface plasmon (collective electronic oscillations at the surface of metals) resonances for sensing. However, it was not until the 1990s […]

A dielectric is a nonconductor of electric charge in which an applied electric field causes a displacement of charge but not a flow of charge. Light propagation through a dielectric medium is determined by the spatial distribution of the material. Photons scatter at local variations of the refractive index. Therefore, how ordered the medium is […]

In 1882, Heinrich Hertz devoted himself to the study of electromagnetism, including the recent and still generally unappreciated work of Maxwell. Two years later he began his famous series of experiments with electromagnetic waves. During the course of this work, Hertz discovered the photoelectric effect, which has had a profound influence on modern physics. The […]

Topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have conducting states on their edge or surface. The conducting surface is not what makes topological insulators unique, but the fact that it is protected due to the combination of spin-orbit interactions and time-reversal symmetry. Researchers are chasing efficient […]

For centuries, metals were employed in optical applications only as mirrors and gratings. New vistas opened up in the late 1970s and early 1980s with the discovery of surface-enhanced Raman scattering and the use of surface plasmon (collective electronic oscillations at the surface of metals) resonances for sensing. However, it was not until the 1990s […]

We have considered in some previous articles the importance of the spin-orbit interaction. But it is interesting to go through some basic concepts we have seen elsewhere once again in order to grasp the surprising discovery we will be talking about below. The analogy for the spin usually goes this way: Imagine that the electron […]