編譯|馮維維
Science, 21 AUG 2025, VOLUME 389 ISSUE 6762
《科學》,2025年8月21日,第389卷,6762期
物理學Physics
Electrical coherent driving of chiral antiferromagnet
手性反鐵磁體的電相干驅動
▲ 作者:YUTARO TAKEUCH, YUMA SATO, YUTA YAMANE, JU-YOUNG YOON, YUKINORI KANNO, TOMOHIRO UCHIMURA, K. VIHANGA DE ZOYSA, JIAHAO HAN, SHUN KANAI, AND SHUNSUKE
▲鏈接:
https://www.science.org/doi/10.1126/science.ado1611
▲摘要:
實現射頻或更高頻率下的反鐵磁態電流驅動仍具挑戰性。研究者報道了對手性反鐵磁體錫錳合金(Mn3Sn)納米點樣品進行全電學千兆赫茲頻段相干驅動的突破性進展。
在亞納秒量級實現了多次試驗的高相干性,且閾值電流對脈沖寬度不敏感——這一特性與鐵磁體中的觀測結果截然不同,從而實現了零場條件下0.1納秒脈沖驅動的1000/1000次可靠翻轉。
這些特征源于反鐵磁激發的慣性特性。研究彰顯了反鐵磁自旋電子學在磁器件操作中兼具高速度與高效率的巨大潛力。
▲ Abstract:
Electric current driving of antiferromagnetic states at radio or higher frequencies remains challenging to achieve. In this study, we report all-electrical, gigahertz-range coherent driving of chiral antiferromagnet manganese-tin (Mn3Sn) nanodot samples. High coherence in multiple trials and threshold current insensitive to pulse width, in contrast to results observed with ferromagnets, were achieved in subnanosecond range, allowing 1000/1000 switching by 0.1-nanosecond pulses at zero field. These features are attributed to the inertial nature of antiferromagnetic excitations. Our study highlights the potential of antiferromagnetic spintronics to combine high speed and high efficiency in magnetic device operations.
Universal coarsening in a homogeneous two-dimensional Bose gas
均勻二維玻色氣體中的普遍粗化
▲ 作者:MARTIN GAZO, ANDREY KARAILIEV, TANISH SATOOR, CHRISTOPH EIGEN, MACIEJ GAKA, AND ZORAN HADZIBABIC
▲鏈接:
https://www.science.org/doi/10.1126/science.ado3487
▲摘要:
遠離平衡態的孤立量子系統的粗化現象是一種典型的多體物理效應,其作用尺度從亞核級延伸至宇宙級,且被預測具有普適動態標度特征。研究者在均勻二維玻色氣體的粗化過程中觀測到普適標度行為,所得指數與解析預測相符。
針對不同初始態,他們通過闡明并修正初始態相關的預標度效應,揭示了有限時間動力學中的普適標度規律。該研究建立的方法實現了冷原子實驗與非平衡場論的直接對標,適用于所有遠離平衡態普適性研究。
▲ Abstract:
Coarsening of an isolated far-from-equilibrium quantum system is a paradigmatic many-body phenomenon, relevant from subnuclear to cosmological length scales and predicted to feature universal dynamic scaling. Here, we observed universal scaling in the coarsening of a homogeneous two-dimensional Bose gas, with exponents that match analytical predictions. For different initial states, we reveal universal scaling in the experimentally accessible finite-time dynamics by elucidating and accounting for the initial-state-dependent prescaling effects. The methods we introduce allow direct comparison between cold-atom experiments and nonequilibrium field theory and are applicable to any study of universality far from equilibrium.
Ultracompact on-chip spectral shaping using pixelated nano-opto-electro-mechanical gratings
超緊湊片上光譜操控
▲ 作者:WEIXIN LIU, SIYU XU, AND CHENGKUO LEE
▲鏈接:
https://www.science.org/doi/10.1126/science.adu8492
▲摘要:
實現動態任意光譜整形能力將通過提供卓越的頻譜效率與網絡靈活性,引發光子技術領域的革命。然而現有光學元件大多具有固定的光譜功能且可調性有限,制約了緊湊型快速光譜整形技術的發展。
研究者提出一種像素化納米光機電(NOEM)光柵,通過機電誘導對稱性破缺實現光柵耦合強度的像素級精確控制,從而研制出微型化(約0.007平方毫米)的光譜整形芯片。他們演示了基于光柵像素的任意光譜響應合成,并通過納米級靜電擾動集合效應,實現了快速(<10納秒)、高對比度(>100分貝)的波長選擇性開關。
這種像素化NOEM光柵以超緊湊的芯片形式提供卓越的光譜操控能力,為下一代光信息網絡、計算架構等應用開辟了新前景。
▲ Abstract:
The ability to shape light spectra dynamically and arbitrarily would revolutionize many photonic systems by offering unparalleled spectral efficiency and network flexibility. However, most existing optical components have rigid spectral functionalities with limited tunability, hindering compact and fast optical spectral shaping. We introduce a pixelated nano-opto-electro-mechanical (NOEM) grating that exploits electromechanically induced symmetry breaking for precise, pixel-level control of grating coupling strength, yielding a miniaturized (~0.007 square millimeters) on-chip spectral shaper. We demonstrate the synthesis of grating pixels for arbitrary spectral responses, and we achieved rapid (<10 nanoseconds), high-contrast (>100 decibels), wavelength-selective switching through collective, nanometer-scale electrostatic perturbations. Our pixelated NOEM grating delivers exceptional spectral manipulation capabilities in an ultracompact, on-chip manner, offering prospects for next-generation optical information networks, computing architectures, and beyond.
Ultrafast elastocapillary fans control agile maneuvering in ripple bugs and robots
超快彈性毛細風扇助力水黽與機器人實現敏捷機動
▲ 作者:VICTOR M. ORTEGA-JIMENEZ, DONGJIN KIM, SUNNY KUMAR, CHANGHWAN KIM, JE-SUNG KOH, AND SAAD BHAMLA
▲鏈接:
https://www.science.org/doi/10.1126/science.adv2792
▲摘要:
水黽(漣漪蟲)利用中肢特化的扁平帶狀結構風扇在急流表面航行。研究表明,該風扇的方向性剛度可實現無需肌肉參與的快速被動式彈性毛細形變,在肢體回縮階段保持可折疊性,而在拖曳式推進階段維持剛性,從而在50毫秒內完成96°全身轉向,最高速度達120體長/秒——與果蠅空中突進速度相當。
基于這種形態功能架構,作者研制出集成1毫克級彈性毛細風扇的昆蟲尺度機器人。通過生物與機器人的對比實驗證實:自形變風扇能顯著提升推力、制動性和機動性。研究揭示了微結構調控界面推進的機制,為敏捷水下微型機器人的緊湊型彈性毛細驅動器建立了設計原則。
▲ Abstract:
Rhagovelia ripple bugs use specialized middle-leg fans with a flat-ribbon architecture to navigate the surfaces of fast-moving streams. We show that the fan’s directional stiffness enables fast, passive elastocapillary morphing, independent of muscle input. This flat-ribbon fan balances collapsibility during leg recovery with rigidity during drag-based propulsion, enabling full-body 96° turns in 50 milliseconds, with forward speeds of up to 120 body lengths per second—on par with fruit fly saccades in air. Drawing from this morphofunctional architecture, we engineered a 1-milligram elastocapillary fan integrated into an insect-scale robot. Experiments with both insects and robots confirmed that self-morphing fans improve thrust, braking, and maneuverability. Our findings link fan microstructure to controlled interfacial propulsion and establish design principles for compact, elastocapillary actuators in agile aquatic microrobots.
生態學Ecology
Light pollution prolongs avian activity
光污染延長鳥類活動時間
▲ 作者:BRENT S. PEASE AND NEIL A. GILBERT
▲鏈接:
https://www.science.org/doi/10.1126/science.adv9472
▲摘要:
光污染會破壞生物賴以生存的光暗周期節律。盡管現有研究(多聚焦于單一物種)已證實光污染會導致鳥類鳴叫晨化,但關于其對不同物種、地域和季節影響的系統性認知仍屬空白。本研究基于全球聲學數據集(超6000萬條聲學探測記錄,涵蓋583種晝行性鳥類),綜合解析光污染對鳥類鳴叫行為的影響。
研究發現光污染平均使鳥類鳴叫時長延長50分鐘。這種效應在具備大眼睛、露天巢穴、遷徙習性及廣域分布特征的物種中尤為顯著,且在繁殖季節最為強烈。活動時長延長可能對鳥類適應性產生負面、中性或積極影響;準確評估這些適應性效應并遏制光污染將成為21世紀保護生物學的重要挑戰。
▲ Abstract:
Light pollution disrupts light–dark cues that organisms use as timetables for life. Although studies—typically focusing on individual species—have documented earlier morning onset of bird vocalization in light-polluted landscapes, a synthesis of light pollution effects across species, space, and season is lacking. We used a global acoustic dataset of more than 60 million detections, representing 583 diurnal bird species, to synthesize effects of light pollution on avian vocalization. On average, light pollution prolonged vocal activity by 50 min. Light pollution responses were strongest for species with large eyes, open nests, migratory habits, and large ranges and during the breeding season. Prolonged activity may confer negative, neutral, or positive fitness effects; documenting these fitness effects and curbing light pollution are challenges for 21st-century conservation.
Fitness benefits of genetic rescue despite chromosomal differences in an endangered pocket mouse
瀕危囊鼠通過遺傳拯救獲得適應度提升
▲ 作者:ARYN P. WILDER, DEBRA M. SHIER, SHAUNA N. D. KING, OLGA DUDCHENKO, ERIK R. FUNK, ANN MISURACA, MARLYS L. HOUCK, WILLIAM B. MILLER, CAITLIN J. CURRY, AND CYNTHIA C. STEINER
▲鏈接:
https://www.science.org/doi/10.1126/science.adn4666
▲摘要:
全球三分之二的物種經歷了種群衰退,使許多物種面臨基因組侵蝕和近交衰退的威脅。遺傳拯救可提升小種群的適應度,但遠交衰退的潛在風險限制了該策略的應用。
研究者通過整合全基因組測序數據與適應度指標,對數百只瀕危太平洋囊鼠進行量化研究。混合育種計劃成功逆轉了殘余種群的基因組侵蝕效應,證明了遺傳拯救的潛在價值。然而染色體數量差異增加了遺傳不相容的風險。
適應度分析表明:雖然混合核型個體的繁殖力可能降低,但低雜合度、高遺傳負荷的非混合個體適應度更低,這表明若種群持續孤立將面臨更大的滅絕風險。
▲ Abstract:
Two-thirds of Earth’s species have undergone population declines, leaving many vulnerable to genomic erosion and inbreeding depression. Genetic rescue can boost the fitness of small populations, but perceived risks of outbreeding depression can limit its use. We quantified these trade-offs in hundreds of endangered Pacific pocket mice (Perognathus longimembris pacificus) by combining whole-genome sequences with fitness data. The impacts of genomic erosion in remnant populations were reversed in an admixed breeding program, suggesting the potential benefits of genetic rescue. However, differences in chromosome numbers increase the risk of genetic incompatibilities. Fitness analyses suggested that although admixed karyotypes may have reduced fertility, non-admixed mice with low heterozygosity and high genetic load had even lower fitness, pointing to a greater risk of extinction if populations remain isolated.
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