Peking University team proposes a twist-angle theory for two-dimensional material interfaces

Recently, a research team led by CAS Member Wang Enge—chair of the board of the Interdisciplinary Institute of Light-Elements Quantum Materials (LEQM)—and Researcher Liu Kaihui, deputy director of the same institute and professor at Peking University’s School of Physics, proposed a twist-angle theory for two-dimensional material interfaces. Through precise design and fabrication, the group induced a rotational mismatch between atomic layers inside hexagonal boron nitride (h-BN), successfully pushing the thickness of twisted h-BN samples to one micrometer and achieving the highest solid-state deep-ultraviolet conversion efficiency on record. The material is expected to become a key component in next-generation high-efficiency extreme-ultraviolet and attosecond light sources. The findings appear in Physical Review Letters.

Source: Beijing Daily

Institute of Physics achieves progress in ultrafast dynamics of polar skyrmions under terahertz excitation

Researchers from the Institute of Physics, Chinese Academy of Sciences / Beijing National Laboratory for Condensed Matter Physics and collaborators have discovered that polar skyrmions in PbTiO?/SrTiO? superlattices host a series of collective modes below 2 THz. Using intense single-cycle terahertz pulses, the team resonantly coupled to these modes and coherently drove the system into a transient, macroscopically polarized hidden phase that remains tunable across the ultra-wide 4 K–470 K temperature window. The work unveils a new mechanism for light-field control of material phases and demonstrates that topological polar textures such as skyrmions are ideal platforms for high-performance optoelectronic devices. The study is published in Nature Physics. The work was supported by Synergetic Extreme Condition User Facility (SECUF).

Source: Institute of Physics, CAS

Institute of Physics achieves atomic-scale control of spin-quantum interference

A team led by Yang Kai, Distinguished Researcher at the Institute of Physics, CAS / Beijing National Laboratory for Condensed Matter Physics, has developed an all-electric method to manipulate spin-quantum interference at the atomic scale. Using a home-built electron-spin-resonance scanning tunneling microscope, the researchers demonstrated atomic-level detection and control of Landau–Zener–Stückelberg–Majorana (LZSM) interference in interacting spin systems. The work lays an important experimental foundation for fast, robust quantum-state manipulation and opens a new route for exploring strongly driven many-body spin dynamics. Results are reported in Nature Communications.

Source: Institute of Physics, CAS

Institute of Physics reveals the heterogeneous ice nucleation pathway via in-situ electron microscopy

The Surface Physics Laboratory at the Institute of Physics, CAS / Beijing National Laboratory for Condensed Matter Physics, led by Researcher Bai Xuedong, has uncovered the kinetic pathway of heterogeneous ice nucleation. Using a self-developed atom-resolved in-situ cryo-electron-microscopy technique, the team tracked how low-pressure water vapor nucleates and crystallizes on cold graphene surfaces. For the first time, the study proves that far from equilibrium, ice can crystallize via a non-classical direct-nucleation route. The finding provides microscopic insight for controlling ice crystallization and offers a new reference for studying phase transitions in condensed-matter systems. The paper is out in Nature Communications.

Source: Institute of Physics, CAS

Institute of Atmospheric Physics clarifies Arctic sea-ice impact on Indian Ocean Dipole events

Scientists at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, CAS—led by Researcher Chen Shangfeng—and collaborators have revealed that winter sea-ice anomalies in the Barents and Greenland Seas significantly influence the evolution of the Indian Ocean Dipole (IOD) in the following autumn. As one of the most important air–sea coupled modes on interannual time scales in the tropical Indian Ocean, understanding IOD development is crucial for improving global short-term climate prediction. The study shows that early-winter Arctic sea-ice anomalies can serve as a key precursor signal for IOD onset and growth, deepening our understanding of how the Arctic climate system modulates tropical air–sea interactions. The work is published in the Journal of Climate.

Source: Institute of Atmospheric Physics, CAS

Institute of Geology and Geophysics introduces geology-guided ambient-noise tomography framework

A team from the Institute of Geology and Geophysics, CAS, together with collaborators, has developed a geology-guided inversion framework for ambient-noise tomography. The method replaces conventional grid-based model parameterization with a three-dimensional interface scheme based on level-set functions. By incorporating prior geological information as explicit constraints, the “geology-driven” approach yields models that better reflect real-world geology and markedly improves imaging of faults and subsurface interfaces, offering a new technical pathway for deep mineral exploration. Results appear in Geophysical Journal International.

Source: Institute of Geology and Geophysics, CAS