If a nucleus has a nonzero spin, it behaves as a small magnet. Therefore, in an external magnetic field, the nuclear magnetic moment vector precesses about the field direction but only certain otientations are allowed by quantum rules. Thus, for hydrogen (spin 1/2) there are two possible states in the presence of a field, each […]
So-called “valleytronics” is a new type of electronics that could lead to faster and more efficient computer logic systems and data storage chips in next-generation devices. Valley electrons are so named because they carry a valley degree of freedom, a pseudospin. This is a new way to harness electrons for information processing that’s in addition […]
Biology • Biomedicine • Computer science • Nanotechnology • Neuroscience • Physics
In 1873, the microscopist Ernst Abbe stipulated a physical limit for the maximum resolution of traditional optical microscopy: 0.2 micrometers, or 200 nanometers (the shortest wavelength for visible light, the extreme limit of violet). This meant that scientists could distinguish whole cells, as well as some parts of the cell called organelles. However, they would […]
A region containing a maximum of potential that prevents a particle on one side of it from passing to the other side is called a potential barrier. The net in a tennis court is in a certain way a potential barrier, as the ball needs to have kinetic energy in excess of the height of […]
Condensed matter • Materials • Nanotechnology • Quantum physics • Theoretical physics
Controlling electron waves by harnessing phase-coherence and interference effects is a cornerstone for future nanoelectronics or quantum computing. To this end, design of platforms with well-defined, narrow, and low-loss propagation channels is essential. Nanoporous graphene (NPG) holds great potential for distributing and controlling currents on the nanoscale. But the effects derived from the wave nature […]
Chemistry • Condensed matter • Materials • Nanotechnology • Quantum physics
Every year the amount of data produced is of the order of magnitude of the Avogadro’s constant, thus 6.028×1023. This trend is supposed to increase even more in the next future. This implies that more and more special metals will be needed. The point is: what might happen if the resources used for manufacturing common […]
Light waves spread and bend as they pass through an aperture or round the edge of a barrier. This is a well-known phenomenon called diffraction. Diffraction imposes a limit to the size of objects that we can observe sharply using light of a given wavelength, for a given microscope will have a minimum aperture, and […]
Condensed matter • Materials • Nanotechnology • Quantum physics
You can read this article because I have used photonics in order to make it possible. It may sound futuristic, but photonics is a technology we use, one way or the other, on a daily basis. Photonic devices are analogous to those used in electronics, but with the electrons replaced by photons. Thus, photonics is […]
Condensed matter • Materials • Nanotechnology • Quantum physics
Some metals, alloys and transition-element salts exhibit a form of magnetism called antiferromagnetism. This occurs below a certain temperature, named after Louis Néel, when an ordered array of atomic magnetic moments spontaneously forms in which alternate moments have opposite directions. There is therefore no net resultant magnetic moment in the absence of an applied field […]
One of the most mysterious features of quantum mechanics is that if two particles (or photons) interact at some point in time then the properties of these particles will remain connected at future times. A consequence of this is that determining the quantum state of one of the particles simultaneously determines the quantum state of […]