Nonlinearity of quantum dot waveguide helps entangle photons

European physicists have studied in detail the interaction of single photons in a photonic crystal waveguide containing a quantum dot. They showed that by varying the duration of the pulses and their delay, it is possible to achieve varying degrees of nonlinearity, as well as control the degree of correlation of light quanta. The study… Continue reading Nonlinearity of quantum dot waveguide helps entangle photons

Physicists have reproduced the chirping effect at the Kukulcan Pyramid

Colombian physicists have reproduced the unusual acoustic effect observed at the Temple of Kukulcan, located on the Yucatan Peninsula in Mexico. The echo of hand clapping at the base of the pyramid resembles the chirping or chirping of a bird. Simulations showed that this effect occurs due to the addition of many waves reflected from… Continue reading Physicists have reproduced the chirping effect at the Kukulcan Pyramid

Spectrometer based on LEGO constructor will make studying physics cheaper

German physics teachers made a universal spectrometer in the Czerny-Turner scheme using LEGO constructors and scrap materials. The authors showed that it can be used to study the spectra of atomic emission, transmission, reflection and fluorescence. Reconfiguring the device for different tasks takes a few minutes, and the total cost of the device does not… Continue reading Spectrometer based on LEGO constructor will make studying physics cheaper

Physicists have proven the importance of the mesoscale for quantum phase transitions

Low-temperature phase transitions in ferromagnets are characterized by destruction of the domain structure. In an article in Nature physicists write that for a theoretical description of the dynamics of such transitions, it is necessary to take into account not only microscopic, but also mesoscale symmetry. This discovery indicates the possibility of the existence of non-classical… Continue reading Physicists have proven the importance of the mesoscale for quantum phase transitions

Metasurfaces emit entangled photons with variable wavelengths

American and German physicists have fabricated thin metasurfaces consisting of arrays of silicon nanocavities that exhibit spontaneous parametric scattering. They showed that such structures are capable of generating entangled photons. Unlike traditional media used for this, metasurfaces have greater flexibility, which allows the wavelength of the resulting photons to be changed by changing the pump… Continue reading Metasurfaces emit entangled photons with variable wavelengths

The Event Horizon Telescope saw the bend of the distant blazar's jet

The Event Horizon Telescope (EHT) has captured the most detailed image yet of the interior of the relativistic jet blazar J1924-2914, whose light took 3.5 billion years to reach Earth. It turned out that as it moves away from the core, the jet begins to bend, and toroidal magnetic fields can act in the region… Continue reading The Event Horizon Telescope saw the bend of the distant blazar's jet

Superfluorescence on single nanoparticles was obtained at room temperature

American physicists were able to induce anti-Stokes superfluorescence of one or several lanthanide-doped nanoparticles at room temperature. The rate of collective emission of ions turned out to be four orders of magnitude greater than ordinary luminescence. This research opens the way to the use of single nanoparticles in the creation of optical processors. The study… Continue reading Superfluorescence on single nanoparticles was obtained at room temperature

Physicists made photons interfere with magnons

Chinese physicists have demonstrated quantum interference between waves of different natures, namely between photons and magnons. They repeated the Hong-Wu-Mandel experiment, where dark polaritons excited in an atomic cloud acted as a beam splitter. By controlling the properties of polaritons using an additional laser, scientists could change the nature of the interference from bosonic to… Continue reading Physicists made photons interfere with magnons

Oscillations of water droplets on the ISS improve understanding of wetting

American physicists studied the natural vibrations of water droplets on hydrophobic substrates in microgravity conditions. To do this, they sent the necessary materials and equipment to the ISS. By filming the vibrations of the drops on camera, the scientists were able to confirm that their previously developed theory of vibrations of free drops works well.… Continue reading Oscillations of water droplets on the ISS improve understanding of wetting

Machine learning predicts the thickness of lead's neutron skin

Physicists have calculated the thickness of the neutron shell in the core of the lead-208 isotope – it is in the range from 0.14 to 0.20 femtometers. To do this, scientists combined calculations from first principles, statistical methods and machine learning. This scheme works faster than direct simulations and in the future it can be… Continue reading Machine learning predicts the thickness of lead's neutron skin