Institute of Chemistry Achieves Important Progress in Printed Optical Metamaterials

Recently, the Song Yanlin research team at the Institute of Chemistry, Chinese Academy of Sciences, in collaboration with partners, proposed a strategy for the efficient and precise printing of metamaterials, establishing a new paradigm for the fabrication of multi-scale optical metamaterials. They successfully achieved low-cost, large-scale, controllable preparation and precise integration of multi-modal optical metamaterials spanning seven orders of magnitude, overcoming the bottleneck in the field of optical metamaterials where nanometer-scale high-precision construction and large-scale preparation have been difficult to reconcile. The research broke through the dilemma where low cost, customization, and mass production of optical metamaterials were hard to achieve simultaneously, opening new avenues for the creation of multi-scale optical novel properties and the broad application of micro- and nano-photonics. The relevant research findings were published in Nature.

Source: Institute of Chemistry, Chinese Academy of Sciences

SECUF Supports Development of a Two-Dimensional Terahertz Coherent Spectroscopy Apparatus with Independently Controlled Dual Pulses

Recently, the Institute of Physics, Chinese Academy of Sciences, in collaboration with multiple teams, developed a novel two-dimensional terahertz spectroscopy platform featuring both high energy conversion efficiency and fully tunable parameters. Based on tilted-wavefront technology, the system generates dual intense terahertz beams from two independent lithium niobate crystals. By introducing a periscopic wire-coupled beam combiner, the system not only largely preserves the electric field intensity of the terahertz radiation but also achieves efficient collinear coupling of the two terahertz beams at the sample and detection regions through the independent alignment degrees of freedom of dual reflectors. This apparatus overcomes the instrumental limitations of two-dimensional coherent terahertz spectroscopy, providing a high-sensitivity characterization platform for exploring complex low-energy excited-state dynamics and strong-field non-perturbative phenomena in condensed matter. This work was carried out at the terahertz unit of the A4 Extreme Condition Spectroscopy Measurement Experimental Station of the Synergetic Extreme Condition User Facility (SECUF). The relevant research findings were published in Review of Scientific Instruments.

Source: Synergetic Extreme Condition User Facility

IAP Publishes Review: Progress and Prospects of Atmospheric Environment Modeling in China

Recently, the Wang Zifa research team at the Institute of Atmospheric Physics, Chinese Academy of Sciences, authored a review paper systematically summarizing the leapfrog development of China’s atmospheric environment models from early “introduction and absorption” to “independent innovation.” Addressing current challenges such as imprecise physical mechanism characterization and the contradiction between computational cost and accuracy demands, the paper proposes four strategic pillars for future development: first, promoting the deep integration of artificial intelligence and mechanistic models, utilizing machine learning to improve computational efficiency while maintaining interpretability; second, leveraging the integrated coupled community model of emissions and atmospheric processes as an opportunity to promote multi-team collaborative development and open-source internationalization; third, exploring advanced numerical techniques such as adaptive mesh refinement; and fourth, embedding atmospheric chemistry more tightly into Earth system models to scientifically characterize complex feedback mechanisms under climate change. This work received technical support from the Earth System Science Numerical Simulator Facility (EarthLab). The relevant research findings were published in Advances in Atmospheric Sciences.

Source: Earth System Science Numerical Simulator Facility (EarthLab)

National Space Science Center Proposes Novel Method for CME-Driven Shock Identification Based on Deep Learning and Numerical Simulation

Recently, the Shen Fang research team at the State Key Laboratory of Solar Activity and Space Weather, National Space Science Center, Chinese Academy of Sciences, proposed and established for the first time a deep learning model based on two-dimensional convolutional neural networks (CNN), capable of automatically, efficiently, and accurately identifying coronal mass ejection (CME)-driven shock structures directly from three-dimensional numerical simulation data. The research team utilized high-resolution three-dimensional magnetohydrodynamic simulation data to develop a CNN-based intelligent identification model, enabling automatic detection of shock structures from three-dimensional numerical simulations of CME propagation. By comparing the performance of the CNN model with traditional methods, results show that the CNN model maintains high accuracy (precision approximately 0.90, recall approximately 0.80), with computational speed improved by approximately fourfold compared to traditional methods, and the reconstructed shock surface is highly consistent with physical methods in three-dimensional morphology. The relevant research findings were published in The Astrophysical Journal.

Source: National Space Science Center, Chinese Academy of Sciences

Peking University Reveals Quantum Secrets of Superconductor-Insulator Phase Transition

Recently, the Wang Jian research group at the International Center for Quantum Materials, School of Physics, Peking University, in collaboration with partners, observed for the first time in a two-dimensional unconventional high-temperature superconductor—the crystalline iron-based high-temperature superconductor Fe(Te,Se) monolayer film (approximately 0.59 nanometers thick)—the local spectroscopic features of disorder-induced superconductor-to-insulator quantum phase transition by controllably introducing disorder through in-situ deposition of iron atom clusters, utilizing scanning tunneling microscopy and scanning tunneling spectroscopy. This reveals the Cooper pair localization origin of the insulating state. This work presents for the first time the local spectroscopic evolution characteristics of the superconductor-insulator quantum phase transition in two-dimensional iron-based high-temperature superconductors under disorder regulation. The relevant results deepen the understanding of low-dimensional high-temperature superconductor quantum phase transitions, particularly the interplay between superconductivity and localization, and demonstrate the important role of local spectroscopic methods in exploring quantum phase transitions and quantum ground states in unconventional superconductors. The relevant research findings were published in Physical Review Letters.

Source: School of Physics, Peking University

Peking University Observes Magnetic-Field-Driven Insulator-to-Superconductor Transition in Rhombohedral Graphene

Recently, the research groups of Lu Xiaobo from the School of Physics at Peking University, and Lin Xi at the Interdisciplinary Institute of Light-Elements Quantum Materials (LEQM), in collaboration with partners, observed a rare phenomenon in rhombohedral multilayer graphene: by applying an in-plane magnetic field, an insulating state can be driven into a superconducting state. This discovery not only challenges conventional superconductivity theory but also provides important clues for exploring novel unconventional superconductivity. The research team fabricated devices with rhombohedral eight-layer graphene moiré superlattices and systematically measured the quantum transport of this system at extremely low temperatures. This work enriches the electronic phase diagram of rhombohedral multilayer graphene and also provides a foundation for exploring superconductivity driven by electronic interactions and their competing physical mechanisms, as well as electrically tunable superconductivity. It further establishes rhombohedral graphene as a highly tunable platform, opening new avenues for constructing unconventional superconductors within the microscopic theoretical framework of superconductivity in van der Waals materials. The relevant research findings were published in Physical Review Letters.

Source: School of Physics, Peking University