Phys.org September 13, 2024 In subduction zones, water expelled from the subducting slab is believed to be involved in seismic activity. However, little is known about its quantity and flow processes. Researchers in Japan showed that the Arima hot springs in western Japan contained high concentrations of water derived from the subducting Philippine Sea slab. A long-term record spanning over half a century revealed that the fraction of slab-derived water exhibited a temporary surge in the year preceding and/or subsequent years of the 1995 Kobe earthquake. In total, an estimated 2.6–4.2 × 105 cubic meters of slab-derived water was introduced in conjunction […]
Tag Archives: S&T Japan
New quantum error correction method uses ‘many-hypercube codes’ while exhibiting beautiful geometry
Phys.org September 6, 2024 Standard approaches to quantum error correction for fault-tolerant quantum computing result in asymptotically zero encoding rates and huge resource overheads. Researchers in Japan proposed concatenated high-rate small-size quantum error-detecting codes as a family of high-rate quantum codes. Their structure allowed for a geometrical interpretation using hypercubes corresponding to logical qubits. Using their method of many-hypercube codes they realized both high rates, e.g., 30% (64 logical qubits are encoded into 216 physical ones), and parallelizability of logical gates. Developing dedicated decoder and encoders, achieved high error thresholds even in a circuit-level noise model. According to the researchers […]
Novel glass-forming liquid electrolyte shows glass transition across broad range
Phys.org September 4, 2024 Recently new ionic fluids such as super-concentrated electrolyte solutions, solvate ionic liquids and deep eutectic solvents have attracted much attention in the field of liquid electrolytes for next-generation electrochemical devices and processes. The basic composition of these new ionic fluids is similar among them; a solvent and a large/excess amount of salt mixtures, though the solvent is sometimes a solid at ambient temperatures. Researchers in Japan found and demonstrated that LiTFSA (TFSA = (CF3SO2)2N−) mixtures with 1,3-propane sultone (PS) or tetrahydrothiophene-1,1-dioxide (SL) yielded a homogeneous liquid at room temperature within a wide range of compositions. In […]
Stacking molecules like plates improves organic solar device performance
Phys.org August 6, 2024 To further improve the efficiency of optoelectronic devices to convert sun light into electricity, researchers in Japan investigated the relationship between aggregation and Exciton binding energy (Eb) and tetraphenylethylene (TPE). Although theoretical calculations and physical measurements in solution showed no apparent differences between DBC-RD and TPE-RD, the pristine films incorporating these molecules showed significantly different levels of electron affinity, ionization potential, and optical gap. Also, DBC-RD had a smaller Eb value compared with that of TPE-RD. However, these molecules showed similar Eb values under dispersed conditions, suggesting that the decreased Eb of DBC-RD in pristine film […]
Ice 0: Researchers discover a new mechanism for ice formation
Phys.org July 26, 2024 The role of the free surface of water in nucleation process remains unclear. Researchers in Japan investigated the microscopic freezing process using molecular dynamics simulations and found that the free surface assisted ice nucleation through an unexpected mechanism. The surface-induced negative pressure enhanced the formation of local structures with a ring topology characteristic of Ice 0-like symmetry, and promoted ice nucleation despite the symmetry differing from ordinary ice crystals. Unlike substrate-induced nucleation via water-solid interactions that occurs directly on the surface, this negative-pressure-induced mechanism promoted ice nucleation slightly inward the surface. Their findings provided a molecular-level […]
Aluminum scandium nitride films: Enabling next-gen ferroelectric memory devices
Phys.org July 19, 2024 By subjecting the films to post-heat-treatment at various temperatures up to 600 °C in both H2 and Ar gases Researchers in Japan investigated the changes in the crystal structure and ferroelectric properties of aluminum scandium nitride films sandwiched between platinum and titanium nitride and titanium nitride electrodes. The remanent polarization underwent slight change, whereas the coercive field was strengthened by approximately 9% because of the post-heat-treatment up to 600 °C irrespective of the atmosphere and electrode material. This change was much smaller than that reported for ferroelectric zirconium dioxide films as well as for lead zirconate titanate and […]
The forbidden propagation of hyperbolic phonon polaritons and applications in near-field energy transport
Phys.org July 8, 2024 GHz burst-mode femtosecond (fs) laser provides distinct characteristics in materials processing as compared with the conventional irradiation scheme of fs laser (single-pulse mode). Researchers in Japan used the moderate pulse interval of 205 ps in the burst pulse for high-quality and high-efficiency micromachining of single crystalline sapphire by laser induced plasma assisted ablation (LIPAA). The preceding pulses in the burst generated plasma by ablation of copper placed behind the sapphire substrate, which interacted with the subsequent pulses to induce ablation at the rear surface of sapphire substrates. The ablation quality, efficiency, and the fabrication resolution were […]
Genetic algorithm enables precise design of phononic crystals
Phys.org July 3, 2024 Phonon engineering at the nanoscale holds immense promise for a myriad of applications. However, the design of phononic devices continues to rely on regular shapes chosen according to long-established simple rules. Researchers in Japan demonstrated an inverse design approach to create a two-dimensional phononic metasurface exhibiting a highly anisotropic phonon dispersion along the main axes of the Brillouin zone. A partial hypersonic bandgap was present along one axis, with gap closure along the orthogonal axis which was achieved through genetically optimized unit cells, with shapes exceeding conventional intuition. They experimentally validated their theoretical predictions using Brillouin […]
Cheap yet ultrapure titanium metal might enable widespread use in industry
Phys.org June 17, 2024 Widespread use of titanium is significantly hampered by its strong affinity to oxygen, resulting in elevated manufacturing costs during the refining, melting, and casting processes. Researchers in Japan introduced a high-throughput technique, that effectively reduced the oxygen content in molten titanium to a level suitable for structural material applications, to streamline the mass production of titanium by seamlessly integrating the refining, melting, and casting processes. The process leveraged the high affinity of rare-earth metals, such as yttrium (Y), for oxygen. They utilized the formation reaction of their oxyhalides (YOF) to directly remove oxygen from liquid titanium […]
Custom-made molecules designed to be invisible while absorbing near-infrared light
Nanowerk June 17, 2024 Molecules that can absorb near-infrared light but not visible light have applications in everything from chemotherapy to photodetectors. Researchers in Japan were able to systematically design a large, complex molecule that does not absorb visible light, (it is completely colorless and transparent) but absorbs near-infrared radiation by carefully constructing molecules that have suitable arrangements of electrons. It showed an absorption band in the NIR region without distinct visible-light absorption, which has led to the establishment of colorless characteristics. Theoretical analyses indicated that the combination of a polyene-like electronic structure with orbital symmetry was important to obtain […]