Nanowerk January 2, 2020 Researchers in Russia analytically investigated properties of magnetostatic surface spin wave propagation in irregular narrow ferromagnetic waveguides that are important elements of magnonic logic. They demonstrated that the confinement effect in the narrow waveguide leads to multimode regime propagation, wave beats, and energy redistribution. These processes can be controlled by tuning the structure and excitation parameters. A gradual change in the waveguide width can be used to vary the spin wave energy density. Our results show that the impact of the width effect and the irregularity of the waveguide on the spin wave propagation are crucial. […]
Scientists create tiny lasers from nanoparticles and plastic beads
Nanowerk December 30, 2019 An international team of researchers (Lawrence Berkeley National Laboratory, UC Berkeley, Columbia University, Italy, Kazakhstan) found that when an infrared laser excites thulium-doped nanoparticles coated on the surface of the beads, the light emitted by the nanoparticles bounces around the inner surface of the bead. When the intensity of light traveling around these beads reaches a certain threshold, the light can stimulate the emission of more light with the exact same color producing intense light at a very narrow range of wavelengths in the beads. When the team exposed the beads to an infrared laser with […]
Scientists develop ceramic materials that are IR-transparent
Nanowerk December 30, 2019 An international team of researchers (Ukraine, Russia, China) developed Y2O3-MgO nanocomposite ceramics with uniform distribution of two phases, microhardness over 11 GPa, and average grain size of 250 nm. It is capable of transmitting over 70% of IR-range with wavelength up to 6,000 nm. The IR transparency increases with the increasing of sintering temperatures, and top values are reached at 1,300-1,350 °C. This is due to the increase of sample density, grain growth, and the reduction of grain boundary length. Due to the submicron size of the grains and their even distribution in the whole volume […]
Soundwaves carry information between quantum systems
Nanowerk December 30, 2019 An international team of researchers ( USA- University of Chicago, UC Santa Barbara, Argonne National Laboratory, Japan) created a hybrid quantum system that acoustically drives transitions in electron spins. The experiment showed a basis for mechanical (strain) control. They developed a theoretical model from a combination of direct experimental observation and density functional theory calculations. From all of this information, they illustrated different types of mechanical strain that drive longer-lasting spins. The material studied was silicon carbide, which has been shown recently to support long-lived spin states that can be accessed optically. The results offer theoretical […]
U.S. military tests radiation belt cleanup in space
Science Magazine January 3, 2020 High-energy electrons, shed by radioactive debris and trapped by Earth’s magnetic field, are fritzing out the satellites’ electronics and solar panels. Now, defense scientists are trying to devise a cure. Three space experiments—one now in orbit and two being readied for launch in 2021—aim to gather data on how to drain high-energy electrons trapped by Earth’s magnetic field in radiation belts encircling the planet…read more. Related article
Top 10 Science and Technology Inventions for the Week of December 27, 2019
01. On-chip light source produces versatile range of wavelengths 02. Brain-like functions emerging in a metallic nanowire network 03. Computing with molecules: A big step in molecular spintronics 04. A fast and inexpensive device to capture and identify viruses 05. Space-time metasurface makes light reflect only in one direction 06. Scientists create thin films with tantalizing electronic properties 07. Scientists discover first antiferromagnetic topological quantum material 08. Electronics at the speed of light 09. Using a material’s ‘memory’ to encode unique physical properties 10. Paving the way for spintronic RAMs: A deeper look into a powerful spin phenomenon And others… […]
Brain-like functions emerging in a metallic nanowire network
Nanowerk December 27, 2019 An international team of researchers (Japan, Australia, USA – UCLA) built a complex brain-like network by integrating numerous silver nanowires coated with a polymer (PVP) insulating layer. A junction between two nanowires forms a synaptic element that behaves like a neuronal synapse forming an intricately interacting “neuromorphic network” when a voltage was applied to it. The research team measured the processes of current pathway formation, retention and deactivation while electric current was flowing through the network and found that these processes always fluctuate as they progress, similar to the human brain’s memorization, learning, and forgetting processes. […]
Computing with molecules: A big step in molecular spintronics
EurekAlert December 23, 2019 An international team of researchers (Germany, Switzerland, France) integrated a spin switching functionality into robust complexes, relying on the mechanical movement of an axial ligand strapped to the porphyrin ring. They demonstrated reversible interlocked switching of spin and coordination induced by electron injection on Ag(111) for this class of compounds. The stability of the two spin and coordination states of the molecules exceeds days. The potential applications of this switching concept go beyond the spin functionality and may turn out to be useful for controlling the catalytic activity of surfaces…read more. TECHNICAL ARTICLE
Device splits and recombines superconducting electron pairs
Phys.org December 27, 2019 Cooper pair splitting (CPS) can induce nonlocal correlation between two normal conductors that are coupled to a superconductor. An international team of researchers (Japan, China, Sweden) investigated CPS by using a Josephson junction of a gate-tunable ballistic InAs double nanowire. The measured switching current in the two nanowires was significantly larger than the sum of the switching current into the respective nanowires, indicating that interwire superconductivity is dominant compared with intrawire superconductivity. From its dependence on the number of propagating channels in the nanowires, the observed CPS was assigned to one-dimensional electron-electron interaction. The results will […]
On-chip light source produces versatile range of wavelengths
Science Daily December 19, 2019 A team of researchers in the US (NIST, University of Maryland, Carnegie Mellon University) has created visible light from an infrared pump by widely separated optical parametric oscillation (OPO) using silicon nanophotonics. The OPO creates signal and idler light in the 700 nm and 1300 nm bands, respectively, with a 900 nm pump. It operates at a threshold power of (0.9±0.1)mW, over 50× smaller than other widely separated microcavity OPO works, which have been reported only in the infrared. This low threshold enables direct pumping without need of an intermediate optical amplifier. The device design […]