Phys.org June 21, 2024 Vertical particle distributions are required to study aerosol–cloud interaction over sea ice comprehensively. An international team of researchers (Germany, USA – University of Colorado) presented vertically resolved measurements of aerosol particle number concentrations and sizes using tethered balloons with the data collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate expedition in the summer of 2020. Radiosoundings, cloud remote sensing data, and 5-day back trajectories supplemented the analysis of thirty-four profiles of aerosol particle number concentration observed in 2 particle size ranges above 150 nm (N>150). The majority of aerosol profiles showed more […]
New photonic chip spawns nested topological frequency comb
Phys.org June 20, 2024 On-chip frequency combs have relied predominantly on single-ring resonators. A team of researchers in the US (University of Maryland, University of Illinois, Northeastern University) experimentally demonstrated the generation of topological frequency combs, in a two-dimensional lattice of hundreds of ring resonators that hosts fabrication-robust topological edge states with linear dispersion. By pumping these edge states, they demonstrated the generation of a nested frequency comb that showed oscillation of multiple edge state resonances across ≈40 longitudinal modes and was spatially confined at the lattice edge. According to the researchers their results provide an opportunity to explore the […]
New tipping point discovered beneath the Antarctic ice sheet
Phys.org June 25, 2024 Recently published studies of the complex hydrography of grounding zones suggest that warm ocean water can intrude large distances beneath the ice sheet, with dramatic consequences for ice dynamics. Researchers in the UK developed a model to capture the feedback between intruded ocean water, the melting it induces and the resulting changes in ice geometry showing a sensitive dependence of the grounding-zone dynamics on this feedback: as the grounding zone widens in response to melting, both temperature and flow velocity in the region increase, further enhancing melting. They found that increases in ocean temperature could lead […]
An optical lens that senses gas
Nanowerk June 26, 2024 Hybrid glasses derived from meltable metal-organic frameworks (MOFs) promise to combine the intriguing properties of MOFs with the universal processing ability of glasses. Researchers in Germany developed optical-quality glasses derived from the zeolitic imidazole framework which allowed them to perform in-depth studies of optical transparency and refraction across the ultraviolet to near-infrared spectral range. Using this fundamental data, they demonstrated the fabrication of micro-optical devices by thermal imprinting. They showed that concave as well as convex lens structures could be obtained at high precision by remelting the glass without trading-off on material quality. This enabled multifunctional […]
Physicists propose time crystal-based circuit board to reduce quantum computing errors
Phys.org June 21, 2024 Time crystalline structures, which can reveal different condensed matter behaviors, can be created in periodically driven systems. However, the potential practical applications of time crystalline structures have yet to be explored. An international team of researchers (Poland, Australia) paved the way for timetronics where temporal lattices were like printed circuit boards for realization of a broad range of quantum devices. The elements of these devices corresponded to structures of dimensions higher than three and could be arbitrarily connected and reconfigured at any moment. Their approach allowed for the construction of a quantum computer, enabling quantum gate […]
Radioactive isotopes trace hidden Arctic currents
Phys.org June 25, 2024 One way to track ocean currents is by tracing, or tracking, radioactive isotopes that humans began generating in the 1950s during nuclear testing. An international team of researchers (Switzerland, Canada) used the transit time of radionuclides to learn about the decades-long path that water from the Atlantic Ocean takes into the Arctic Ocean’s Canada Basin. Transit Time Distribution (TTD) model mean ages indicated water takes 25–35 years to reach the Canada Basin from the entrance of the Arctic. Mode ages obtained from the model yielded shorter transport times of 20–32 years. These age estimates agree with […]
Researchers create new class of materials called ‘glassy gels’
Phys.org June 19, 2024 By swelling with solvent, glassy polymers can become gels that are soft and weak yet have enhanced extensibility. The marked changes in properties arise from the solvent increasing free volume between chains while weakening polymer–polymer interactions. A team of researchers in the US (North Carolina State University, University of Nebraska) developed a unique class of materials called glassy gels with desirable properties of both glasses and gels by solvating polar polymers with ionic liquids at appropriate concentrations. The ionic liquid increases free volume and extensibility despite the absence of conventional solvent. It forms strong and abundant […]
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 discover new flat electronic bands, paving way for advanced quantum materials
Phys.org June 25, 2024 Flat electronic bands expected to show proportionally enhanced electron correlations are being pursued in d-electron-based systems with crystalline lattices that feature destructive electronic interference. Such flat bands are generically located far away from the Fermi energy, which limits their capacity to partake in the low-energy physics. An international team of researchers (USA – Rice University, Stony Brook University, independent organization, Spain, Austria) showed that electron correlations produce emergent flat bands that are pinned to the Fermi energy. They demonstrated this effect within a Hubbard model, in the regime described by Wannier orbitals where an effective Kondo […]
Researchers move floating objects with soundwaves
Phys.org July 25, 2024 Light and sound waves can move objects through the transfer of linear or angular momentum. However, the stringent requirement for a highly controlled, low-reverberant and static environment still hinders the applicability of these techniques in many scenarios. An international team of researchers (Kazakhstan, Switzerland, France, Austria) overcame this challenge and demonstrated the manipulation of objects in disordered and dynamic media by optimally tailoring the momentum of sound waves iteratively in the far field. The method did not require information about the object’s physical properties or the spatial structure of the surrounding medium but relied only on […]