Nanowerk August 14, 2023 Many scientists believe that the key to designing and programming more complex and useful artificial nanosystems relies on our ability to understand and better employ molecular languages developed by living organisms, namely allostery (molecule binds and modifies the structure of another molecule) and multivalency, (facilitates (or not) the binding of a third molecule by simply increasing its binding interface). As a proof-of-concept researchers in Canada engineered a highly programmable DNA-based switch that could be triggered by either a multivalent or an allosteric DNA activator. By precisely designing the binding interface of the multivalent activator, they showed […]
From light to motion: Shaping surfaces with light
Nanowerk August 12, 2023 Using confocal microscopy researchers in Finland characterized dynamic photoinduced wrinkle erasure enabled by photomechanical changes in supramolecular polymer-azo complexes. Different photoactive molecules were compared to 4-hydroxy-4′-dimethylaminoazobenzene (OH-azo-DMA). The characteristic erasure times of wrinkles were assessed by using an image processing algorithm. The results confirmed that the photoinduced movement on the topmost layer could be successfully transferred to the substrate. Furthermore, the chosen supramolecular strategy allowed decoupling the effect of molecular weight of the polymer and photochemistry of the chromophore, allowing quantitative comparison of wrinkling erasure efficiency of different materials and providing a facile way to optimize […]
Magnonic computing: Faster spin waves could make novel computing systems possible
Phys.org August 16, 2023 Spin waves are ideal candidates for wave-based computing, but the construction of magnetic circuits is blocked by the lack of an efficient mechanism to excite long-running exchange spin waves with normalized amplitudes. An international team of researchers (Austria, Ukraine, Germany, Czech Republic) solved the problem by exploiting a deeply nonlinear phenomenon for forward volume spin waves in 200-nm-wide nanoscale waveguides and validated their concept using microfocused Brillouin light scattering spectroscopy. An unprecedented nonlinear frequency shift of more than 2 GHz was achieved, corresponding to a magnetization precession angle of 55° and enabled the excitation of spin […]
Nanomaterial offers new way to control fire
Nanowerk August 14, 2023 High-temperature flames can be difficult to control how it interacts with the material being processed. An international team of researchers (USA – Iowa State University, North Carolina State University, Ames National Laboratory, Canada) developed a technique that utilizes a molecule-thin protective layer to control how the flame’s heat interacts with the material allowing users to finely tune the characteristics of the processed material. They pyrolyzed alkysilanes grafted onto cellulose fibers into non-flammable SiO2 terminating surface ignition propagation, hence stalling flame propagating. Sustaining high temperatures, however, triggered gnition in the bulk of the fibers but under restricted […]
New paint gives extra insulation, saving on energy, costs, and carbon emissions
Phys.org August 14. 2023 Space heating and cooling consume ~13% of global energy every year. To thermally isolate the space of concern and minimize the heat exchange with the outside environment has been recognized as one effective solution. Researchers at Stanford University developed a universal category of colorful low-emissivity paints to form bilayer coatings consisting of an infrared (IR)-reflective bottom layer and an IR-transparent top layer in colors. High mid-infrared reflectance (up to ~80%) was achieved, which is more than 10 times as conventional paints in the same colors, efficiently reducing both heat gain and loss from/to the outside environment. […]
New property of hydrogen predicted
Phys.org August 7, 2023 Recently it was predicted based on ab initio quantum Monte Carlo simulations that, in a uniform electron gas, the peak ω0 of the dynamic structure factor S(q,ω) exhibits an unusual nonmonotonic wave number dependence, where dω0/dq<0, at intermediate q, under strong coupling conditions. Researchers in Germany predicted that this nonmonotonic dispersion resembling the roton-type behavior known from superfluids should be observable in a dense, partially ionized hydrogen plasma. Based on a combination of path integral Monte Carlo simulations and linear response results for the density response function, they presented the approximate range of densities, temperatures and […]
Potential application of unwanted electronic noise in semiconductors
Science Daily August 10, 2023 Random noise in magnetic materials is of potential use in systems such as spiking neuron devices, random number generators and probability bits. An international team of researchers (South Korea, China, USA – Harvard University, Montana State University) has shown electrically tunable magnetic fluctuations and random telegraph noise in multilayered vanadium-doped tungsten diselenide (WSe2) using vertical tunnelling heterostructure devices composed of graphene/vanadium-doped WSe2/graphene and magnetoresistance measurements. They identified bistable magnetic states through discrete Gaussian peaks in the random telegraph noise histogram and the 1/f2 features of the noise power spectrum. Three categories of fluctuation were detected: […]
Scientists discover novel way of reading data in antiferromagnets, unlocking their use as computer memory
Nanowerk August 14, 2023 The Berry curvature and quantum metric are the imaginary part and real part, respectively, of the quantum geometric tensor which characterizes the topology of quantum states. The former is known to generate a zoo of important discoveries such as quantum Hall effect and anomalous Hall effect (AHE), while the consequences of the quantum metric have rarely been probed by transport. An international team of researchers (Singapore, Israel, China, Japan) has found quantum metric-induced nonlinear transport, including both nonlinear AHE and diode-like nonreciprocal longitudinal response, in thin films of a topological antiferromagnet, MnBi2Te4. They have revealed that […]
Scientists invent smallest known way to guide light
Science Daily August 11, 2023 Addressing the optical mismatch between components typically results in compromises in size and performance of chip-scale optical circuits for practical devices. Researchers at the University of Chicago showed that they could confine and guide light in an ultrathin two-dimensional (2D) material (<1 nanometer thick). They made three-atom-thick waveguides—δ waveguides—based on wafer-scale molybdenum disulfide (MoS2) monolayers that could guide visible and near-infrared light over millimeter-scale distances with low loss and an efficient in-coupling. The extreme thinness provided a light-trapping mechanism analogous to a δ-potential well in quantum mechanics and enabled the guided waves that were essentially […]
Using magnetic effects in electrons for a hundredfold reduction in the power consumption of future chips
Nanowerk August 15, 2023 As electronic devices shrink, they become more powerful, use more energy and produce more heat. A consortium of researchers is working under an EU funded HORIZON project, “SPIDER” (Spin Wave Computing for Ultimately-Scaled Hybrid Low-Power Electronics), to investigate how changes to the magnetic properties of semiconductors could achieve a hundredfold reduction in the power consumption of computer chips. They have developed a computer system that combines magnonics with conventional computing technology with its standard semiconductor systems. They produced an interface between the conventional computer and a spin wave circuit made from sapphire or gadolinium gallium garnet […]