Phys.org November 29, 2024 Strongly driven nonlinear optical processes such as spontaneous parametric down-conversion and spontaneous four-wave mixing can produce multiphoton nonclassical beams of light which have applications in quantum information processing and sensing. In contrast to the low-gain regime, new physical effects arise in a high-gain regime due to the interactions between the nonclassical light and the strong pump driving the nonlinear process. Researchers in Canada described and experimentally observed a gain-induced group delay between the multiphoton pulses generated in a high-gain type-II spontaneous parametric down-conversion source. The researchers concluded that since the group delay introduced distinguishability between the […]
Tag Archives: S&T Canada
Scientists uncover light absorbing properties of achiral materials
Phys.org September 30, 2024 In chiral metasurfaces, the lack of symmetry leads to differential absorption when probed with chiral light either in the form of circular polarization or helical phase fronts. Researchers in Canada demonstrated differential absorption of asymmetric twisted light beams, known as helical dichroism, which exist in an array and a single achiral structure and could be controlled. When extended to chiral structures, these asymmetrical chiral light modes enabled enhancing and tuning chiroptical sensitivity. According to the researchers their technique offers more control parameters than just changing the OAM value. Selective response to asymmetric helical light beams was […]
Printed electronics material can store 1,000 times more charge than current forms
Phys.org August 19, 2024 Making the Internet of Things a reality will require the type of circuitry and advanced operations that are only possible with electronics that can function in both positive and negative voltage modes. Researchers in Canada developed a new material zwitterion composed of an imidazolium tethered to an anionic sulfonyl(trifluoromethane sulfonyl)imide group as an alternative dielectric material to traditional ionic liquids. The zwitterion not only melted below 100 °C but also proved to be nonhygroscopic. By blending this compound with poly(methyl methacrylate) over a range of concentrations and thicknesses, they made high-capacitance organic dielectric materials. Experiments suggested […]
Smart fabrics detect and repel pathogens to prevent hospital infections
Nanowerk August 20, 2024 Healthcare textiles serve as key reservoirs for pathogen proliferation. Researchers in Canada developed a new class of Smart Fabrics (SF) with integrated “Repel, Kill, and Detect” functionalities, which they achieved through a blend of hierarchically structured microparticles, modified nanoparticles, and an acidity-responsive sensor. It showed good resilience against aerosol and droplet-based pathogen transmission, showed a reduction exceeding 99.90% compared to uncoated fabrics across various drug-resistant bacteria. Experiments involving bodily fluids from healthy and infected individuals revealed a significant reduction of 99.88% and 99.79% in clinical urine and feces samples compared to uncoated fabrics. According to the […]
Small but mighty: Why microbes could be part of climate solutions
Phys.org August 12, 2024 Methane and nitrous oxide (N2O) are greenhouse gases that rank second and third behind carbon dioxide as primary contributors to global warming and climate change. Outside of fossil sources, these gases are emitted by microorganisms as they interact with their environment. Researchers in Canada many strategies have targeted reduction of methane emissions. However, the microbial communities that live in these settings can respond to mitigation efforts by producing more N2O, which reduces or even negates the positive climate impact. Mitigation approaches often have not accounted for these trade-offs, and doing so requires additional monitoring to make […]
Researchers develop tuneable anti-counterfeiting material
Phys.org June 24, 2024 Nanosized PersL materials could blend more easily with solvents and allow printing patterns with fine details. MgGeO3 is one of the frequently employed lattice hosts for PersL phosphors. It can accommodate divalent ions such as Mn2+ to produce deep red PersL. To date, the only reported method of synthesizing nanosized Mn-doped MgGeO3 (MGO:Mn) is the sol–gel method. The synthesis product has a wide particle size distribution and suffers severe aggregation. Researchers in Canada synthesized MGO:Mn nanorods with a uniformly distributed morphology. The nanorods exhibit more intense and longer-lasting PersL. By detailed comparative study between the MGO:Mn […]
Researchers use new cobalt-modified nano material to make fuel cells more robust, sustainable
Phys.org October 11, 2023 Using the Pt metal as the shell material of the catalyst in polymer electrolyte membrane fuel cells not only increases the surface area but also creates an interfacial interaction between the core metal and platinum, which results in enhanced catalytic activity. Researchers in Canada surface doped Pd@Pt nanoparticles with cobalt to further boost their durability and activity. Characterizing the synthesized catalyst with X-ray absorption fine structure at the Pt L3-edge and cobalt K-edges, together with performance tests, revealed information about the effect of the dopants on the catalytic activity of catalysts. The results of the local […]
Decoding how molecules ‘talk’ to each other to develop new nanotechnologies
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 […]
Capturing non-transparent ultrafast scenes
Phys.org May 26, 2023 Real-time imaging modalities with ultrahigh temporal resolutions are required for capturing ultrashort events on picosecond timescales for unveiling many fundamental mechanisms in physics, chemistry, and biology. Current single-shot ultrafast imaging schemes operate only at conventional optical wavelengths, being suitable solely within an optically transparent framework. Researchers in Canada leveraged the unique penetration capability of terahertz radiation to demonstrate a single-shot ultrafast terahertz photography system that could capture multiple frames of a complex ultrafast scene in non-transparent media with sub-picosecond temporal resolution. By multiplexing an optical probe beam in both the time and spatial-frequency domains, they encoded […]
Researchers advance insights into cause of ripples on icicles
Science Daily December 5, 2022 Icicles that have grown from slightly impure water develop ripples around their circumference. The ripples have a near-universal wavelength and are thought to be the result of a morphological instability. Researchers in Canada used laboratory-grown icicles and various species of impurities, including fluorescent dye, to show that a certain fraction of the impurities remains trapped inside the icicle, forming inclusions within the ice. The inclusions were organized into chevron patterns aligned with the peaks of the ripples. Within the chevrons, there was a substructure of crescent-shaped structures. They also examined the crystal grain structure of […]