編譯|未玖
Nature, 23 January 2025, Volume 637, Issue 8047
《自然》2025年1月23日，第637卷，8047期
天文學Astronomy
Field–particle energy transfer during chorus emissions in space
空間合聲波發射過程中的場-粒子能量轉移
▲ 作者：C. M. Liu, B. N. Zhao, J. B. Cao, C. J. Pollock, C. T. Russell, Y. Y. Liu, et al.
▲鏈接：
https://www.nature.com/articles/s41586-024-08402-z
▲摘要：
合聲波是太空中自然發生的最強電磁輻射之一，可能產生對人類和衛星有害的輻射。盡管合聲波已引起了人們極大的興趣，并被深入研究了幾十年，但其產生和演變仍存在高度爭議。
與合聲波由行星偶極磁場控制的傳統預期相反，研究組在不存在磁偶極影響的地球中性片區域中觀測到重復升調合聲波。利用美國航空航天局（NASA）MMS任務的高節奏數據，研究組展示了波場和波內三維電子分布的超快測量，這為波相空間中合聲波電子相互作用和電子空穴的發展提供了證據。他們發現這些波與反平行于波磁場的共振電流有關，正如非線性波理論所預測的那樣。
研究組估計了合聲波內部的非線性場-粒子能量傳遞，發現波從局部熱電子中提取能量，這與由不穩定性分析得出的波的正增長率保持一致。該觀測可能有助于解決長期以來關于合聲波發射的爭議，并有助于理解在空間和天體物理環境中觀測到的能量傳輸。
▲ Abstract：
Chorus waves are some of the strongest electromagnetic emissions naturally occurring in space and can cause radiation that is hazardous to humans and satellites. Although chorus waves have attracted extreme interest and been intensively studied for decades, their generation and evolution remain highly debated. Here, in contrast to the conventional expectation that chorus waves are governed by planetary magnetic dipolar fields, we report observations of repetitive, rising-tone chorus waves in the terrestrial neutral sheet, where the effects of the magnetic dipole are absent. Using high-cadence data from NASA’s MMS mission, we present ultrafast measurements of the wave fields and three-dimensional electron distributions within the waves, which provides evidence for chorus–electron interactions and the development of electron holes in the wave phase space. We found that the waves are associated with resonant currents antiparallel to the wave magnetic field, as predicted by nonlinear wave theory. We estimated the nonlinear field–particle energy transfer inside the waves, finding that the waves extract energy from local thermal electrons, in line with the positive growth rate of the waves derived from an instability analysis. Our observations may help to resolve long-standing controversies regarding chorus emissions and in gaining an understanding of the energy transport observed in space and astrophysical environments.
材料科學Materials Science
Superconductivity in twisted bilayer WSe2
扭曲雙層WSe2的超導性
▲ 作者：Yiyu Xia, Zhongdong Han, Kenji Watanabe, Takashi Taniguchi, Jie Shan & Kin Fai Mak
▲鏈接：
https://www.nature.com/articles/s41586-024-08116-2
▲摘要：
莫爾材料已實現了平電子帶以及由與平帶相關的強關聯驅動的量子相。人們僅在石墨烯納米材料中觀察到超導性，在石墨烯之外的莫爾材料（如半導體莫爾材料）中尚未發現穩健的超導性，這仍是一個謎，并挑戰了人們目前對平帶超導性的理解。
研究組報道了在具有六方莫爾晶格的3.5°和3.65°扭曲雙層二硒化鎢（WSe2）中觀察到的穩健超導性。在半帶填充和零外部位移場附近出現超導性。兩種情況下的最佳超導轉變溫度約為200mK，約占有效費米溫度的1~2%；后者的值與高溫銅酸鹽超導體的值相當，并表明存在強配對。
超導體在半帶填充物上下與兩種不同的金屬相鄰；通過調節外部位移場，可使其連續躍遷至相關絕緣子。在庫侖誘導的電荷局域化邊緣觀察到超導性，表明其根源在于強電子關聯。
▲ Abstract：
Moiré materials have enabled the realization of flat electron bands and quantum phases that are driven by the strong correlations associated with flat bands. Superconductivity has been observed, but only in graphene moiré materials. The absence of robust superconductivity in moiré materials beyond graphene, such as semiconductor moiré materials, has remained a mystery and challenged our current understanding of superconductivity in flat bands. Here we report the observation of robust superconductivity in both 3.5° and 3.65° twisted bilayer tungsten diselenide (WSe2), which hosts a hexagonal moiré lattice. Superconductivity emerges near half-band filling and zero external displacement fields. The optimal superconducting transition temperature is about 200mK in both cases and constitutes about 1–2% of the effective Fermi temperature; the latter is comparable to the value in high-temperature cuprate superconductors and suggests strong pairing. The superconductor borders on two distinct metals below and above half-band filling; it undergoes a continuous transition to a correlated insulator by tuning the external displacement field. The observed superconductivity on the verge of Coulomb-induced charge localization suggests roots in strong electron correlations.
All-solid-state Li–S batteries with fast solid–solid sulfur reaction
具有快速固-固硫反應的全固態鋰硫電池
▲ 作者：Huimin Song, Konrad Münch, Xu Liu, Kaier Shen, Ruizhuo Zhang, Timo Weintraut, et al.
▲鏈接：
https://www.nature.com/articles/s41586-024-08298-9
▲摘要：
全固態鋰硫電池（ASSLSB）具有高比能、高安全性和低成本的優點，是下一代儲能的理想選擇。然而，因三相邊界處緩慢的固-固硫氧化還原反應（SSSRR）導致的速率性能差和循環壽命短的問題仍有待解決。
研究組展示了一種由硫代磷酸碘化鋰（LBPSI）玻璃相固體電解質（GSEs）實現的快速SSSRR。基于I-和I2/I3-之間的可逆氧化還原，固體電解質（SE）不僅作為超離子導體，還可作為表面氧化還原介質，促進了固-固兩相邊界處的緩慢反應，從而大大增加了活性位點的密度。
通過這種機制，ASSLSB表現出超快充電能力，在2C（30°C）充電時顯示出1497 mAh g-1硫的高比容量，而在20C時仍保持784 mAh g-1硫。值得注意的是，在60°C下以150 C的極限速率充電時，仍可實現432 mAh g-1硫的比容量。
此外，該電池在5C（25°C）下具有超過25000次循環的優異循環穩定性，容量保持率為80.2%。研究組希冀這項氧化還原介導SSSRR的工作將為開發高能量且安全的先進ASSLSBs鋪平道路。
▲ Abstract：
With promises for high specific energy, high safety and low cost, the all-solid-state lithium–sulfur battery (ASSLSB) is ideal for next-generation energy storage. However, the poor rate performance and short cycle life caused by the sluggish solid–solid sulfur redox reaction (SSSRR) at the three-phase boundaries remain to be solved. Here we demonstrate a fast SSSRR enabled by lithium thioborophosphate iodide (LBPSI) glass-phase solid electrolytes (GSEs). On the basis of the reversible redox between I- andI2/I3-, the solid electrolyte (SE)—as well as serving as a superionic conductor—functions as a surficial redox mediator that facilitates the sluggish reactions at the solid–solid two-phase boundaries, thereby substantially increasing the density of active sites. Through this mechanism, the ASSLSB exhibits ultrafast charging capability, showing a high specific capacity of 1,497 mAhg-1sulfur on charging at 2C (30°C), while still maintaining 784mAh g-1sulfur at 20C. Notably, a specific capacity of 432 mAh g-1sulfur is achieved on charging at an extreme rate of 150C at 60°C. Furthermore, the cell demonstrates superior cycling stability over 25,000 cycles with 80.2% capacity retention at 5C (25°C). We expect that our work on redox-mediated SSSRR will pave the way for developing advanced ASSLSBs that are high energy and safe.
化學Chemistry
Bilayer nanographene reveals halide permeation through a benzene hole
雙層納米石墨烯揭示鹵化物通過苯環孔滲透
▲ 作者：M. A. Niyas, Kazutaka Shoyama, Matthias Grüne & Frank Würthner
▲鏈接：
https://www.nature.com/articles/s41586-024-08299-8
▲摘要：
石墨烯是一種單層sp2雜化碳同素異形體，它對除氫以外的所有原子實體都不可滲透。缺陷的引入允許選擇性氣體滲透；人們已努力控制這些缺陷的大小以獲得更高的選擇性。離子等除氣體以外其他實體的滲透，因其在海水淡化、檢測和凈化方面的潛在應用而具有重大科學意義。然而，到目前為止，對鹵化物滲透的精確實驗觀察仍然未知。
研究組展示了鹵化物通過分子納米石墨烯中單個苯環大小的缺陷進行滲透。利用超分子自組裝原理，他們創造了一個穩定的納米石墨烯雙分子層。由于雙層納米石墨烯的空腔只能通過兩個埃大小的窗口進入，任何被捕獲在空腔中的鹵化物都必須通過單個苯環孔滲透。該實驗揭示了氟化物、氯化物和溴化物通過單個苯環孔的滲透性，而碘化物是不可滲透的。
單層納米石墨烯中氯化物的高滲透性和雙層納米石墨烯中選擇性結合鹵化物的證據，為將石墨烯中的單個苯環缺陷用于人工鹵化物受體、過濾膜以及進一步創建多層人工氯化物通道提供了潛力。
▲ Abstract：
Graphene is a single-layered sp2-hybridized carbon allotrope, which is impermeable to all atomic entities other than hydrogen. The introduction of defects allows selective gas permeation; efforts have been made to control the size of these defects for higher selectivity. Permeation of entities other than gases, such as ions, is of fundamental scientific interest because of its potential application in desalination, detection and purification. However, a precise experimental observation of halide permeation has so far remained unknown. Here we show halide permeation through a single benzene-sized defect in a molecular nanographene. Using supramolecular principles of self-aggregation, we created a stable bilayer of the nanographene. As the cavity in the bilayer nanographene could be accessed only by two angstrom-sized windows, any halide that gets trapped inside the cavity has to permeate through the single benzene hole. Our experiments reveal the permeability of fluoride, chloride and bromide through a single benzene hole, whereas iodide is impermeable. Evidence for high permeation of chloride across single-layer nanographene and selective halide binding in a bilayer nanographene provides promise for the use of single benzene defects in graphene for artificial halide receptors, as filtration membranes and further to create multilayer artificial chloride channels.
Entanglement and iSWAP gate between molecular qubits
分子量子位之間的糾纏和iSWAP門
▲ 作者：Lewis R. B. Picard, Annie J. Park, Gabriel E. Patenotte, Samuel Gebretsadkan, David Wellnitz, Ana Maria Rey, et al.
▲鏈接：
https://www.nature.com/articles/s41586-024-08177-3
▲摘要：
量子計算和量子模擬依賴于具有可控交互的長壽命量子位。人們提出捕獲極性分子可作為一種有前景的量子計算平臺，具有可擴展性和單粒子尋址能力，同時仍可利用其固有復雜性和強耦合性。
單量子態制備和單個捕獲分子的超精細旋轉態相干性的最新進展使這種量子位頗具前景，分子間偶極相互作用產生糾纏。然而，通用的雙量子位門尚未在分子中得到證實。
研究組通過本征分子資源，利用單獨捕獲的X1Σ+ NaCs分子來實現雙量子位iSWAP門。通過將分子在1.9 μm的距離上交互664 μs，在兩個分子同時存在的情況下創建了保真度為94（3）%的最大糾纏貝爾態。利用運動-旋轉耦合，沿軸向捕獲方向測量了最低運動態的殘余激發，并發現其是退相干的主要來源。
最后，研究組在編碼量子位的基態旋轉能級內確定了兩個非交互的超精細態。通過在交互和非交互狀態之間轉換來切換交互，以實現iSWAP門。研究組通過測量其邏輯真值表來驗證門的性能。
▲ Abstract：
Quantum computation and simulation rely on long-lived qubits with controllable interactions. Trapped polar molecules have been proposed as a promising quantum computing platform, offering scalability and single-particle addressability while still leveraging inherent complexity and strong couplings of molecules. Recent progress in the single quantum state preparation and coherence of the hyperfine-rotational states of individually trapped molecules allows them to serve as promising qubits, with intermolecular dipolar interactions creating entanglement. However, universal two-qubit gates have not been demonstrated with molecules. Here we harness intrinsic molecular resources to implement a two-qubit iSWAP gate using individually trapped X1Σ+ NaCs molecules. By allowing the molecules to interact for 664μs at a distance of 1.9μm, we create a maximally entangled Bell state with a fidelity of 94(3)% in trials in which both molecules are present. Using motion–rotation coupling, we measure residual excitation of the lowest few motional states along the axial trapping direction and find them to be the primary source of decoherence. Finally, we identify two non-interacting hyperfine states within the ground rotational level in which we encode a qubit. The interaction is toggled by transferring between interacting and non-interacting states to realize an iSWAP gate. We verify the gate performance by measuring its logical truth table.
地球科學Earth Science
Clouds reduce downwelling longwave radiation over land in a warming climate
在氣候變暖的情況下，云層減少了陸地的下行長波輻射
▲ 作者：Lei Liu, Yi Huang & John R. Gyakum
▲鏈接：
https://www.nature.com/articles/s41586-024-08323-x
▲摘要：
云層極大地影響著地球的能量平衡。觀測約束云輻射反饋是一種明顯不確定的氣候反饋機制，對改進氣候變化的預測至關重要，但迄今為止，這仍是一個難以捉摸的目標，且海洋和陸地上的反饋可能不同。
研究組展示了大平原南部陸地上的局部負地表長波云反饋，受到光譜分辨下行長波輻射的直接長期觀測的約束。這種在大平原南部地區的負云反饋導致下行長波輻射每10年減少1.77±1.15Wm-2，這表明云的變化可能部分調節了陸地上溫室氣體濃度增加和大氣溫度升高的變暖效應。具體而言，該結果源于一種最佳的光譜指紋識別方法，旨在通過利用光譜分辨輻射長期記錄中的獨特光譜特征，將表面長波云反饋與其他地表強迫和反饋分離開來。
此外，研究組還表明，該結果并非特定于站點：在再分析和衛星數據集中，通常在陸地上觀察到由變暖氣候下低云覆蓋減少引起的負地表長波云反饋。該發現建立了驗證陸地氣候模型性能所需的輻射強迫和反饋的關鍵觀測基準。
▲ Abstract：
Clouds greatly influence the Earth’s energy balance. Observationally constraining cloud radiative feedback, a notably uncertain climate feedback mechanism, is crucial for improving predictions of climate change but, so far, remains an elusive objective, and the feedback may be different over the ocean versus over land. Here we show a local negative surface longwave cloud feedback over land at the southern Great Plains site, constrained by direct long-term observation of spectrally resolved downwelling longwave radiance. This negative cloud feedback at the southern Great Plains site causes a 1.77 ± 1.15 W m-2per decade change in downwelling longwave radiation and suggests that cloud changes may partially modulate the warming effect of increased greenhouse gas concentrations and atmospheric temperatures over land. Specifically, our results are derived from an optimal spectral fingerprinting method designed to separate surface longwave cloud feedback from other surface forcings and feedbacks, by making use of their unique spectral signatures in the long-term record of spectrally resolved radiances. Furthermore, we show that the results are not site specific: negative surface longwave cloud feedbacks, primarily induced by decreasing low cloud cover in warming climates, are commonly observed over land in reanalysis and satellite datasets. Our findings establish a pivotal observational benchmark of radiative forcing and feedback needed for validating climate model performance over land.
本文鏈接：《自然》（20250123出版）一周論文導讀http://www.lensthegame.com/show-11-16815-0.html
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