Science Daily February 17, 2021 To investigate complex, functional, nanoscopic structures of semiconductor devices researchers in Germany have developed an imaging procedure using extreme ultraviolet coherence tomography. It is based on optical coherence tomography used in ophthalmology. They demonstrated the method at a laser-driven broadband extreme ultraviolet radiation source, based on high-harmonic generation. They showed that, besides nanoscopic axial resolution, the spectral reflectivity of all layers in a sample can be obtained using algorithmic phase reconstruction. This provides localized, spectroscopic, material-specific information of the sample. The method can be applied in semiconductor production, lithographic mask inspection, or quality control of multilayer […]
Wafer-scale production of graphene-based photonic devices
Science Daily February 11, 2021 Graphene has been recently proposed to be integrated with silicon photonics to meet the challenges of next generation optical communication to increase the available bandwidth while reducing the size, cost, and power consumption of photonic integrated circuits. An international team of researchers (Italy, UK) focused on graphene photodetectors for high speed datacom and telecom applications based on the photo-thermo-electric effect, allowing for direct optical power to voltage conversion, zero dark current, and ultra-fast operation. They reported on a chemical vapour deposition graphene photodetector based on the photo-thermoelectric effect, integrated on a silicon waveguide, providing frequency […]
Top 10 Science and Technology Inventions for the Week of February 12, 2021
01. Scientists create armor for fragile quantum technology 02. Silicon waveguides move us closer to faster, light-based logic circuits 03. UMass Amherst team helps demonstrate spontaneous quantum error correction 04. ‘Multiplying’ light could be key to ultra-powerful optical computers 05. Capturing Free-Space Optical Light for High-Speed WiFi 06. Inductance based on a quantum effect has the potential to miniaturize inductors 07. ‘Magnetic graphene’ forms a new kind of magnetism 08. New concept for rocket thruster exploits the mechanism behind solar flares 09. Quantum effects help minimize communication flaws 10. Quantum systems learn joint computing And others… 21 per cent of […]
21 per cent of all citations go to the elite
Science Daily February 9, 2021 Researchers in Denmark used a linked dataset of more than 4 million authors and 26 million scientific papers spanning 15 years and 118 scientific disciplines to quantify trends in cumulative citation inequality and concentration at the author level. They found that a small stratum of elite scientists accrues increasing citation shares, and that citation inequality is on the rise across the natural sciences, medical sciences, and agricultural sciences. The rise in citation concentration has coincided with a general inclination toward more collaboration. While increasing collaboration and full-count publication rates go hand in hand for the […]
Capturing Free-Space Optical Light for High-Speed WiFi
Duke University February 9, 2021 Visible and infrared light can carry more data than radio waves, but has always been confined to a hard-wired, fiber-optic cable. A team of researchers in the US (Duke University, industry) has demonstrated a low-loss plasmonic metasurface that can collect fast-modulated light with a 3 dB bandwidth exceeding 14 GHz and a 120º acceptance angle and convert it to a directional source with an overall efficiency of ∼30%. This exhibits a 910-fold increase in the overall fluorescence and a 133-fold emission rate enhancement. The metasurface was created over macroscopic areas with scalable techniques and the […]
Inductance based on a quantum effect has the potential to miniaturize inductors
Phys.org February 5, 2021 The magnitude of the conventional inductance is proportional to the volume of the inductor’s coil, which hinders the miniaturization of inductors. Researchers in Japan have demonstrated an inductance of quantum-mechanical origin, generated by the emergent electric field induced by current-driven dynamics of spin helices in a magnet. In microscale rectangular magnetic devices with nanoscale spin helices, they observed a typical inductance as large as −400 nanohenry, comparable in magnitude to that of a commercial inductor, but in volume about a million times smaller. The inductance is enhanced by nonlinearity in current and shows non-monotonous frequency dependence, […]
‘Magnetic graphene’ forms a new kind of magnetism
EurekAlert February 8, 2021 An international team of researchers ( UK, Uzbekistan, Russia, France, USA – Oak Ridge National Laboratory, Vietnam, South Korea, Czech Republic) was able to control the conductivity and magnetism of iron thiophosphate (FePS3) which undergoes a transition from an insulator to a metal when compressed. Using new techniques to measure the magnetic structure up to record-breaking high pressures, they found that magnetism survives, but gets modified into new forms, giving rise to new quantum properties in a new type of magnetic metal. The ‘spin’ of the electrons has been shown to be the source of magnetism. […]
‘Multiplying’ light could be key to ultra-powerful optical computers
EurekAlert February 8, 2021 An international team of researchers (Russia, UK) found that optical systems can combine light by multiplying the wave functions describing the light waves instead of adding them and may represent a different type of connections between the light waves. If the coupling and light intensity is right, the light multiplies, affecting the phases of the individual pulses, giving away the answer to the problem. They found that there is no need to project the continuous light phases onto ‘0’ and ‘1’ states necessary for solving problems in binary variables. Instead, the system tends to bring about […]
New concept for rocket thruster exploits the mechanism behind solar flares
Science Daily January 28, 2021 Current plasma thrusters that use electric fields to propel the particles can only produce low specific impulse. The device proposed by researchers at Princeton Plasma Physics Laboratory would apply magnetic fields to cause particles of plasma to shoot out of a rocket and propel the craft forward. The particles are accelerated using magnetic reconnection which also occurs in tokamaks. They showed that the new plasma thruster concept can generate exhaust with velocities of hundreds of kilometers per second, 10 times faster than those of other thrusters. According to the researchers the new concept provides the […]
New mathematical method for generating random connected networks
Science Daily February 10, 2021 Many natural and human-made networks, such as computer, biological or social networks have a connectivity structure that critically shapes their behavior. Existing algorithms that create connected networks with a specific number of connections for each node suffer from uncontrolled bias potentially compromising the conclusions of the study. Researchers in Germany have developed a new method for the random sampling of connected networks with a specified degree sequence considering both the case of simple graphs and that of loopless multigraphs. Their method builds on a recently introduced novel sampling approach that constructs graphs with given degrees […]