Phys.org December 7, 2021 According to the researchers in Hong Kong the absence of shear force in the air, or fluids, makes sound waves longitudinal. Synthetic shear force may arise if the air is discretized into “meta-atoms,” whose collective motion can give rise to a transverse sound on the macroscopic scale. To implement this idea they designed micropolar metamaterial like a complex network of resonators. Air was confined inside the mutually connected resonators, forming the meta-atoms. Through theoretical calculations they showed that the collective motion of meta-atoms produces the shear force, which gives rise to the transverse sound with spin-orbit […]
Scientists document the presence of quantum spin liquids, a never-before-seen state of matter
Phys.org December 2, 2021 To reproduce the microscopic physics found in condensed matter systems an international team of researchers (USA – Harvard University, MIT, Austria) used a simulator that allows the researchers to create programmable shapes like squares, honeycombs, or triangular lattices to engineer different interactions and entanglements between ultracold atoms. Quantum spin liquids display none of that magnetic order because, essentially, there is a third spin added, turning the checker box pattern to a triangular pattern making it a “frustrated” magnet where the electron spins can’t stabilize in a single direction. The researchers used the simulator to create their […]
Sodium-based material yields stable alternative to lithium-ion batteries
Science Daily December 6, 2021 In earlier sodium batteries the anode would grow dendrites that can cause the battery to electrically short and even catch fire or explode. A team of researchers in the US (UT Austin, Los Alamos National Laboratory) developed a new anode material, sodium antimony telluride intermetallic — Na metal composite (NST-Na), by rolling a thin sheet of sodium metal onto an antimony telluride powder, folding it over on itself, and repeating many times. This process results in a very uniform distribution of sodium atoms that makes it less likely to form dendrites or surface corrosion than […]
Transforming materials with light
Nanowerk December 8, 2021 Although there are strategies to drastically alter electronic and magnetic properties by optically inducing non-trivial band topologies, emergent spin interactions and superconductivity, methods of coherently engineering optical properties on demand are far less understood. An international team of researchers (Caltech, UC Santa Barbara, South Korea) has demonstrated coherent control and giant modulation of optical nonlinearity in a van der Waals layered magnetic insulator, manganese phosphorus trisulfide (MnPS3). They observed a coherent on–off switching of its optical second harmonic generation efficiency on the timescale of 100 femtoseconds with no measurable dissipation. At driving electric fields of the order […]
Top 10 Science and Technology Inventions for the Week of December 3, 2021
01. Color-changing magnifying glass gives clear view of infrared light 02. Getting quantum dots to stop blinking 03. Magnons vs electrons: A new spin on computer processing 04. New chip hides wireless messages in plain sight 05. Potential step toward new superconductors 06. Programmable interaction between quantum magnets 07. Researchers propose method to increase charge of supercapacitors 08. Researchers propose a simpler design for quantum computers 09. Revolutionary intelligent transistor can be adapted to perform very different tasks 10. Shrinking qubits for quantum computing with 2D materials And others… This 3D-Printer Uses Ink Made From Microbes to Print Blobs That […]
This 3D-Printer Uses Ink Made From Microbes to Print Blobs That Are Alive
Science Alert December 1, 2021 Based on the living cells ability to synthesize molecular components and precisely assemble them to build living functional architectures under ambient conditions microbial engineering has produced materials for various applications. However, building 3D structures in arbitrary patterns and shapes has been a challenge. A team of researchers in the US (Harvard University, Northeastern University, Harvard Medical School) has developed a bioink (microbial ink) that is produced entirely from genetically engineered microbial cells, programmed to perform a bottom-up, hierarchical self-assembly of protein monomers into nanofibers, and nanofiber networks that comprise extrudable hydrogels. They demonstrated the 3D […]
Biomanufacturing: Coming Soon to a Galaxy Near You?
DARPA November 22, 2021 DARPA announced Biomanufacturing: Survival, Utility, and Reliability beyond Earth (B-SURE) program which offers a novel approach for in-situ manufacturing in far-forward locations, including space and provide DoD-relevant molecules and materials and alleviate supply chain burdens associated with space operations. To accomplish this goal, B-SURE will collect data on the microbial utilization of space-based alternative feedstocks, optimization of microbial growth in variable gravities, and mitigation strategies for identified effects of galactic cosmic radiation on microbial growth and bioproduction. The 18-month effort involves three tracks – Track 1 “Alternative Feedstock Utilization” will determine which alternative feedstocks can be […]
Breaking the symmetry of sound waves allows the sound to be directed to a certain place
Phys.org November 29, 2021 An international team of researchers (China, Spain) constructed a topological gallery insulator using sonic crystals made of thermoplastic rods that are decorated with carbon nanotube films, which act as a sonic gain medium by virtue of electro-thermoacoustic coupling. By engineering specific non-Hermiticity textures to the activated rods, they were able to break the chiral symmetry of the whispering-gallery modes, which enables the out-coupling of topological ‘audio lasing’ modes with the desired handedness. Adding gain makes it possible to amplify to break the chiral symmetry. The laboratory tests have demonstrated that when these elements are applied, the […]
Color-changing magnifying glass gives clear view of infrared light
Phys.org December 2, 2021 An international team of researchers (UK, Belgium, Spain) used a single layer of molecules to absorb the mid-infrared light inside their vibrating chemical bonds. These shaking molecules donate their energy to visible light that they encounter, ‘upconverting’ it to emissions closer to the blue end of the spectrum, which can then be detected by visible-light cameras. The challenge was to make sure the quaking molecules met the visible light quickly enough. They devised a way to sandwich single molecular layers between a mirror and tiny chunks of gold to twist and squeeze light. The researchers emphasize […]
Getting quantum dots to stop blinking
Science Daily November 22, 2021 Quantum dots tendency to blink off at random intervals has hampered its use for biochemical applications. Researchers at MIT have come up with a way to control this unwanted blinking by firing a beam of mid-infrared laser light for an infinitesimal moment which eliminates the quantum dot’s blinking for a relatively long period. According to the researchers the cause of the blinking phenomenon probably has to do with extra electrical charges, such as extra electrons, attaching to the outer part of the quantum dots, altering the surface properties providing alternative pathways for the extra energy […]