物理学Physics

▲ 作者：KRYSTIAN NOWAKOWSKI, HITESH AGARWAL, SERGEY SLIZOVSKIY, ROBIN SMEYERS, XUEQIAO WANG, ZHIREN ZHENG, ET AL.

▲ 链接：

https://www.science.org/doi/10.1126/science.adu5329

▲ 摘要：

单个光量子探测对于量子信息、空间探索、先进机器视觉和基础科学至关重要。

在这项工作中，研究组介绍了一种利用莫尔材料中高光敏非平衡电子相的单光子探测机制。利用双层石墨烯/六方氮化硼超晶格中的可调谐带，他们设计了负微分电导和能够探测单光子的灵敏双稳态。在这种状态下，研究组展示了在中红外（11.3微米）和可见波长（675纳米）以及温度高达25开尔文下的单光子计数。

该探测器为宽带高温量子技术提供了前景，与互补的金属氧化物半导体兼容，可无缝集成到光子集成电路中。分析结果表明，潜在的机制源于超晶格诱导的负微分速度。

▲ Abstract：

Detecting individual light quanta is essential for quantum information, space exploration, advanced machine vision, and fundamental science. In this work, we introduce a single-photon detection mechanism using highly photosensitive nonequilibrium electron phases in moiré materials. Using tunable bands in bilayer graphene/hexagonal boron nitride superlattices, we engineer negative differential conductance and a sensitive bistable state capable of detecting single photons. Operating in this regime, we demonstrate single-photon counting at mid-infrared (11.3 micrometers) and visible wavelengths (675 nanometers) and temperatures up to 25 kelvin. This detector offers prospects for broadband, high-temperature quantum technologies with complementary metal-oxide semiconductor compatibility and seamless integration into photonic-integrated circuits. Our analysis suggests that the underlying mechanism originates from superlattice-induced negative differential velocity.

▲ 作者：BENO?T RICHARD, REBECCA BOLL, SOURAV BANERJEE, JULIA M. SCH?FER, ZOLTAN JUREK, GREGOR KASTIRKE, ET AL.

▲ 链接：

https://www.science.org/doi/10.1126/science.adu2637

▲ 摘要：

由于海森堡测不准原理，分子的结构即使在基态也会围绕其平均几何构型涨落。通过实验观察这种基本的量子效应（特别是揭示结构量子涨落的集体性质），对于复杂分子而言仍是一个尚未解决的挑战。

在这项工作中，研究组通过X射线自由电子激光诱导11原子分子的库仑爆炸实现了这一目标。研究表明，结构涨落表现在通过同步检测单个分子原子碎片获得的离子动量的相关变化中。

尽管研究组的测量只覆盖了整个33维动量空间的一小部分，但该分析方案实现了探测这些变化，从而建立了一种使用库仑爆炸获取高维结构动力学信息的通用方法。

▲ Abstract：

Because of the Heisenberg uncertainty principle, the structure of a molecule fluctuates about its mean geometry, even in the ground state. Observing this fundamental quantum effect experimentally—particularly, revealing the collective nature of the structural quantum fluctuations—remains an unmet challenge for complex molecules. In this work, we achieved this for an 11-atom molecule by inducing its Coulomb explosion with an x-ray free-electron laser. We show that the structural fluctuations manifest themselves in correlated variations of ion momenta obtained through coincident detection of the atomic fragments from individual molecules. Our analysis scheme allows extracting these variations, despite our measurements covering only a fraction of the full 33-dimensional momentum space, thereby establishing a general approach for extracting information on high-dimensional structural dynamics using Coulomb explosion.

材料科学Materials Science

▲ 作者：BINBIN HE, YUANYUAN HE, WENHUI WANG, YINGZHI SUN, SHENGWEN KONG, JIN HUANG, ET AL.

▲ 链接：

https://www.science.org/doi/10.1126/science.adt2741

▲ 摘要：

磁电传感有望用于柔性传感器，以最小的功耗提供对电场和磁场的精确检测。然而，其实际应用受限于磁电效应较弱和整体性能有限，特别是在机械应变下。

研究组通过界面共结晶策略制备了稳健的磁电聚合物—无机纳米复合材料。通过利用二硒化钒（VSe2）单层上的重氮化学，他们在铁磁性VSe2和铁电聚偏氟乙烯（PVDF）纳米晶体之间创建了一个亚分子平面界面。这种高度结晶的界面几乎没有可移动聚合物链，从而限制了能量耗散并增强了界面能量传递。

该可扩展复合薄膜具有优异的磁电性能，磁电容系数为23.6%。这些薄膜实现了超快磁电检测，与传统传感器相比，速度提高了近10倍，有望实现多功能材料（如热电制冷器）集成到可穿戴设备。

▲ Abstract：

Magnetoelectric sensing holds promise for flexible sensors, offering precise detection of both electric and magnetic fields with minimal power consumption. However, its practical use has been constrained by weak magnetoelectric effects and limited overall performance, particularly under mechanical strain. Herein, we fabricated robust magnetoelectric polymer-inorganic nanocomposites through an interfacial cocrystallization strategy. By leveraging diazonium chemistry on vanadium diselenide (VSe2) monolayers, we created a submolecular-flat interface between ferromagnetic VSe2 and ferroelectric poly(vinylidene fluoride) (PVDF) nanocrystals. This highly crystalline interface has few mobile polymer chains and thus limits energy dissipation and enhances interfacial energy transfer. The scalable composite films show exceptional magnetoelectric performance, with a magnetocapacitive coefficient of 23.6%. These films enable ultrafast magnetoelectric detection, approaching a 10-fold increase in speed compared with conventional sensors, and offer opportunities for integrating multifunctional materials such as thermoelectric coolers into wearable devices.

▲ 作者：SANGWON LEE, MICHAEL PILIPCHUK, CAN YILDIRIM, DUNCAN GREELEY, QIANYING SHI, TRACY D. BERMAN, ET AL.

▲ 链接：

https://www.science.org/doi/10.1126/science.adv3460

▲ 摘要：

镁合金的重量是铝的三分之二，有望减少交通工具的燃料消耗。这些进步取决于人们优化变形孪晶理想效应的能力，变形孪晶是在机械应力下形成的三维（3D）微观结构域。

此前仅通过表面或薄膜测量来进行表征，研究组使用晶体塑性有限元分析支持的暗场X射线显微镜，在介观视场上对嵌入晶粒内的变形孪晶进行了3D原位表征。结果揭示了三重结在孪晶形核中的作用以及孪晶生长的顺序和不规则性，表明孪晶—晶粒结、孪晶—孪晶结和孪晶界是位错局部积累的位置。

▲ Abstract：

At two-thirds the weight of aluminum, magnesium alloys have the potential to reduce the fuel consumption of transportation vehicles. These advancements depend on our ability to optimize the desirable versus undesirable effects of deformation twins, which are three-dimensional (3D) microstructural domains that form under mechanical stresses. Previously only characterized through surface or thin-film measurements, we present 3D in situ characterization of deformation twinning inside an embedded grain over mesoscopic fields of view using dark-field x-ray microscopy supported by crystal plasticity finite element analysis. The results revealed the role of triple junctions on twin nucleation and the sequence and irregularity of twin growth and showed that twin-grain junctions, twin-twin junctions, and twin boundaries were the sites of localized dislocation accumulation.

生命科学Life Science

▲ 作者：EVAN HELLER HTTPS://ORCID.ORG/0009-0005-4405-7089, NAINA KURUP HTTPS://ORCID.ORG/0000-0003-2160-0622, AND XIAOWEI ZHUANG

▲ 链接：

https://www.science.org/doi/10.1126/science.adn6712

▲ 摘要：

神经元膜骨架采用周期性晶格结构，其中肌动蛋白丝由内收蛋白和原调节性蛋白覆盖，形成环状结构，沿神经突由光谱蛋白四聚体连接。这种膜相关周期性骨架（MPS）对许多神经元功能都很重要。

使用活细胞超分辨率成像，研究组意外发现MPS是动态的，在轴突中进行局部解体和重塑。MPS重塑是由钙信号驱动的，通过蛋白激酶C介导的内收蛋白磷酸化导致肌动蛋白环失稳，并通过钙蛋白酶降解光谱蛋白。

Formin是一种肌动蛋白成核和聚合酶，在MPS重塑和维持中起双重作用。MPS重塑通过神经元活动增强，并在功能上促进内吞作用。该研究结果强调了动态膜骨架结构在神经元功能中的重要性。

▲ Abstract：

The membrane skeleton in neurons adopts a periodic lattice structure in which actin filaments, capped by adducin and tropomodulin, form ring-shaped structures connected by spectrin tetramers along neurites. This membrane-associated periodic skeleton (MPS) is important for many neuronal functions. Using live-cell super-resolution imaging, we found that the MPS is surprisingly dynamic, undergoing local disassembly and reformation constitutively in axons. MPS remodeling is driven by calcium signaling, leading to actin-ring destabilization through protein kinase C–mediated adducin phosphorylation and to spectrin degradation by calpain. Formin, an actin-nucleating and -polymerizing enzyme, plays a dual role in MPS remodeling and maintenance. MPS remodeling is enhanced by neuronal activity and functionally facilitates endocytosis. Our results highlight the importance of a dynamic membrane skeletal structure in neuronal function.