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发布日期：2024-08-27 作者：开博
Nature, 20 June 2024, Volume 630 Issue 8017
《天然》, 2024年6月20日，第630卷，8017期
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物理学Physics
A secondary atmosphere on the rocky exoplanet 55 Cancri e
系外行星巨蟹座55e上的年夜气
▲ 作者：Renyu Hu, Aaron Bello-Arufe, Michael Zhang, Kimberly Paragas, Mantas Zilinskas, Christiaan van Buchem, Michael Bess, Jayshil Patel, Yuichi Ito, Mario Damiano, Markus Scheucher, Apurva V. Oza, Heather A. Knutson, Yamila Miguel, Diana Dragomir, Alexis Brandeker Brice-Olivier Demory
▲ 链接：
https://www.nature.com/articles/s41586-024-07432-x
▲ 摘要：
描画岩石系外行星的特点是天文学的中间方针，但是迄今为止，在岩石系外行星上寻觅年夜气的成果要末是年夜气质量的严酷上限，要末是不肯定的成果。相当在1.95个地球半径和8.8个地球质量的行星——巨蟹座55 e（以下简称55Cnc e），首要由岩石构成，均衡温度约为2000 K，可能有一个挥发性的包层（包括由C、H、O、N、S和P元素组合而成的份子），占其半径的百分之几。
研究者操纵透射光谱对该行星进行了普遍的不雅测，并在宽光度波段丈量了其热辐射。这些不雅测不撑持原始H2/ he主导的年夜气，但不克不及终究肯定该行星是不是有次级年夜气。
研究者报导了由詹姆斯韦布太空千里镜取得的行星4 ~ 12μm的热发射光谱。丈量成果解除了这颗行星是一个熔岩世界，被由蒸发岩石构成的淡薄年夜气所笼盖的可能性，注解它是一个真实的挥发性年夜气，可能富含二氧化碳或一氧化碳。这类年夜气可以从岩浆海洋中释放出来，并由岩浆海洋保持。
▲ Abstract：
Characterizing rocky exoplanets is a central aim of astronomy, and yet the search for atmospheres on rocky exoplanets has so far resulted in either tight upper limits on the atmospheric mass or inconclusive results. The 1.95REarth and 8.8MEarth planet 55?Cancri?e (abbreviated 55?Cnc?e), with a predominantly rocky composition and an equilibrium temperature of around 2,000?K, may have a volatile envelope (containing molecules made from a combination of C, H, O, N, S and P elements) that accounts for up to a few percent of its radius. The planet has been observed extensively with transmission spectroscopy and its thermal emission has been measured in broad photometric bands. These observations disfavour a primordial H2/He-dominated atmosphere but cannot conclusively determine whether the planet has a secondary atmosphere. Here we report a thermal emission spectrum of the planet obtained by the NIRCam and MIRI instruments aboard the James Webb Space Telescope (JWST) from 4 to 12?μm. The measurements rule out the scenario in which the planet is a lava world shrouded by a tenuous atmosphere made of vaporized rock and indicate a bona fide volatile atmosphere that is probably rich in CO2 or CO. This atmosphere can be outgassed from and sustained by a magma ocean.
A site-resolved two-dimensional quantum simulator with hundreds of trapped ions
具稀有百个捕捉离子的位置分辩二维量子摹拟器
▲ 作者：S.-A. Guo, Y.-K. Wu, J. Ye, L. Zhang, W.-Q. Lian, R. Yao, Y. Wang, R.-Y. Yan, Y.-J. Yi, Y.-L. Xu, B.-W. Li, Y.-H. Hou, Y.-Z. Xu, W.-X. Guo, C. Zhang, B.-X. Qi, Z.-C. Zhou, L. He L.-M. Duan
▲ 链接：
https://www.nature.com/articles/s41586-024-07459-0
▲ 摘要：
年夜量子位容量和单个读出能力是年夜范围量子计较和摹拟的两个要害要求。作为量子信息处置的首要物理平台之一，离子阱已在一维保罗阱中实现了数十个具有位置分辩读出的离子的量子摹拟，在二维 Penning阱中实现了数百个具有全局可不雅测值的离子的量子摹拟。
但是，将这两个功能集成到一个系统中依然很是具有挑战性。研究者报导了512个离子在二维维格纳晶体中的不变捕捉和其横向活动的边带冷却。
研究者操纵单次丈量中的位置分辩率，在准绝热制备的基态中不雅察到丰硕的空间相干模式，可以经由过程将丈量的双自旋相干与计较的集体声子模式和经典摹拟退火进行比力，来验证量子摹拟成果。
研究进一步切磋了Ising模子在横向场中的猝灭动力学，以演示量子采样使命。该研究为摹拟经典辣手的量子动力学和利用二维离子阱量子摹拟器运行有噪声的中等范围量子算法摊平了道路。
▲ Abstract：
A large qubit capacity and an individual readout capability are two crucial requirements for large-scale quantum computing and simulation. As one of the leading physical platforms for quantum information processing, the ion trap has achieved a quantum simulation of tens of ions with site-resolved readout in a one-dimensional Paul trap and of hundreds of ions with global observables in a two-dimensional (2D) Penning trap. However, integrating these two features into a single system is still very challenging. Here we report the stable trapping of 512 ions in a 2D Wigner crystal and the sideband cooling of their transverse motion. Enabled by the site resolution in the single-shot measurement, we observe rich spatial correlation patterns in the quasi-adiabatically prepared ground states, which allows us to verify quantum simulation results by comparing the measured two-spin correlations with the calculated collective phonon modes and with classical simulated annealing. We further probe the quench dynamics of the Ising model in a transverse field to demonstrate quantum sampling tasks. Our work paves the way for simulating classically intractable quantum dynamics and for running noisy intermediate-scale quantum algorithms using 2D ion trap quantum simulators.
化学物理Chemical Physics
Acceleration of radiative recombination for efficient perovskite LEDs
加快高效钙钛矿LED辐射复合
▲ 作者：Mengmeng Li, Yingguo Yang, Zhiyuan Kuang, Chenjie Hao, Saixue Wang, Feiyue Lu, Zhongran Liu, Jinglong Liu, Lingjiao Zeng, Yuxiao Cai, Yulin Mao, Jingshu Guo, He Tian, Guichuan Xing, Yu Cao, Chao Ma, Nana Wang, Qiming Peng, Lin Zhu, Wei Huang Jianpu Wang
▲ 链接：
https://www.nature.com/articles/s41586-024-07460-7
▲ 摘要：
平板显示器和固态照明利用对更高效、更亮的薄膜发光二极管（LED）的需求日趋增加，这鞭策了对三维钙钛矿的研究。这些材料表示出高电荷迁徙率和低量子效力降落，使它们成为实现具有加强亮度的高效LED的有但愿的候选者。
为了提高led的效力，在增进辐射复合的同时尽可能削减非辐射复合是相当主要的。各类钝化策略已被用在下降三维钙钛矿薄膜的缺点密度，接近单晶的程度。但是，迟缓的辐射（双份子）重组使三维钙钛矿的光致发光量子效力（PLQEs）低在80%，致使LED器件的外部量子效力（EQEs）低在25%。
研究者提出了一种双添加剂结晶方式，可以构成高效三维钙钛矿，实现了96%的出色PLQE。这类方式增进了四边形FAPbI3钙钛矿的构成，以其高激子连系能而著名，有用地加快了辐射复合。
研究实现了具有创记载峰值EQE为32.0%的钙钛矿LED，即便在100 mA cm?2的高电流密度下，效力依然年夜在30.0%。这些发现为推动高效、高亮度钙钛矿LED的成长供给了有价值的看法。
▲ Abstract：
The increasing demands for more efficient and brighter thin-film light-emitting diodes (LEDs) in flat-panel display and solid-state lighting applications have promoted research into three-dimensional (3D) perovskites. These materials exhibit high charge mobilities and low quantum efficiency droop, making them promising candidates for achieving efficient LEDs with enhanced brightness. To improve the efficiency of LEDs, it is crucial to minimize nonradiative recombination while promoting radiative recombination. Various passivation strategies have been used to reduce defect densities in 3D perovskite films, approaching levels close to those of single crystals. However, the slow radiative (bimolecular) recombination has limited the photoluminescence quantum efficiencies (PLQEs) of 3D perovskites to less than 80%, resulting in external quantum efficiencies (EQEs) of LED devices of less than 25%. Here we present a dual-additive crystallization method that enables the formation of highly efficient 3D perovskites, achieving an exceptional PLQE of 96%. This approach promotes the formation of tetragonal FAPbI3 perovskite, known for its high exciton binding energy, which effectively accelerates the radiative recombination. As a result, we achieve perovskite LEDs with a record peak EQE of 32.0%, with the efficiency remaining greater than 30.0% even at a high current density of 100?mA?cm?2. These findings provide valuable insights for advancing the development of high-efficiency and high-brightness perovskite LEDs.
Atomic dynamics of electrified solid–liquid interfaces in liquid-cell TEM
液电池TEM中带电固液界面的原子动力学
▲ 作者：Qiubo Zhang, Zhigang Song, Xianhu Sun, Yang Liu, Jiawei Wan, Sophia B. Betzler, Qi Zheng, Junyi Shangguan, Karen C. Bustillo, Peter Ercius, Prineha Na
▲ 链接：
https://www.nature.com/articles/s41586-024-07479-w
▲ 摘要：
带电固液界面在与能源、生物和地球化学相干的各类电化学进程中起着要害感化。带电界面上的电子和质量传递可能致使布局改变，从而显著影响反映路子。例如，电催化剂在反映进程中的概况重组会对催化机理和反映产品发生本色性的影响。
虽然它很主要，但直接探测电偏置下固液界面的原子动力学是具有挑战性的，由于它被埋在液体电解质中，并且今朝经由过程液体进行原位成像的手艺空间分辩率有限。研究者开辟了用在透射电子显微镜（TEM）的进步前辈聚合物电化学液体电池，可以或许直接监测铜催化二氧化碳电还原反映（CO2ERs）进程中ESLIs的原子动力学。
研究者不雅察揭露了一个波动的液体状无定形界面。它产生可逆的晶—非晶布局改变，并沿通电铜概况活动，从而经由过程界面层介导结晶铜概况重构和质量损掉。及时不雅察和理论计较的连系揭露了由电荷激活的电解质概况反映引发的非晶化介导的重组机制。经由过程操纵原位成像能力，该的成果为摸索原子动力学和其在触及ESLIs的普遍系统中的影响供给了很多机遇。
▲ Abstract：
Electrified solid–liquid interfaces (ESLIs) play a key role in various electrochemical processes relevant to energy, biology and geochemistry. The electron and mass transport at the electrified interfaces may result in structural modifications that markedly influence the reaction pathways. For example, electrocatalyst surface restructuring during reactions can substantially affect the catalysis mechanisms and reaction products. Despite its importance, direct probing the atomic dynamics of solid–liquid interfaces under electric biasing is challenging owing to the nature of being buried in liquid electrolytes and the limited spatial resolution of current techniques for in situ imaging through liquids. Here, with our development of advanced polymer electrochemical liquid cells for transmission electron microscopy (TEM), we are able to directly monitor the atomic dynamics of ESLIs during copper (Cu)-catalysed CO2 electroreduction reactions (CO2ERs). Our observation reveals a fluctuating liquid-like amorphous interphase. It undergoes reversible crystalline–amorphous structural transformations and flows along the electrified Cu surface, thus mediating the crystalline Cu surface restructuring and mass loss through the interphase layer. The combination of real-time observation and theoretical calculations unveils an amorphization-mediated restructuring mechanism resulting from charge-activated surface reactions with the electrolyte. Our results open many opportunities to explore the atomic dynamics and its impact in broad systems involving ESLIs by taking advantage of the in situ imaging capability.
化学Chemistry
Reproducible graphene synthesis by oxygen-free chemical vapour deposition
无氧化学气相沉积法合成可再生石墨烯
▲ 作者：Jacob Amontree, Xingzhou Yan, Christopher S. DiMarco, Pierre L. Levesque, Tehseen Adel, Jordan Pack, Madisen Holbrook, Christian Cupo, Zhiying Wang, Dihao Sun, Adam J. Biacchi, Charlezetta E. Wilson-Stokes, Kenji Watanabe, Takashi Taniguchi, Cory R. Dean, Angela R. Hight Walker, Katayun Barmak, Richard Martel James Hone
▲ 链接：
https://www.nature.com/articles/s41586-024-07454-5
▲ 摘要：
化学气相沉积（CVD）在铜上合成石墨烯的方式自初次演示以来已被普遍采取。但是，CVD发展的石墨烯在根本科学和利用中的普遍利用一向遭到可反复性和质量挑战的阻碍。我们发现微量氧是决议低压CVD发展石墨烯的发展轨迹和质量的要害身分。
无氧化学气相沉积（OF-CVD）合成速度快，可反复性高，动力学可以用紧凑的模子来描写，而添加微量氧会按捺成核缓和慢/不完全发展。经由过程概况污染、拉曼D峰的呈现和电导率的下降来评估氧对石墨烯质量的影响。在无氧前提下发展的外延石墨烯是无污染的，没有可检测到的D峰。
颠末干燥转移和氮化硼封装后，其室温电输运行动接近在剥离的石墨烯。石墨门控器件表示出杰出的整数和分数目子霍尔效应。经由过程强调消弭微量氧的主要性，新研究作为此后CVD系统的设计和运行供给了指点。由OF-CVD 合成的可反复性和质量的提高将普遍影响石墨烯的根本研究和利用。
▲ Abstract：
Chemical vapour deposition (CVD) synthesis of graphene on copper has been broadly adopted since the first demonstration of this process. However, widespread use of CVD-grown graphene for basic science and applications has been hindered by challenges with reproducibility and quality. Here we identify trace oxygen as a key factor determining the growth trajectory and quality for graphene grown by low-pressure CVD. Oxygen-free chemical vapour deposition (OF-CVD) synthesis is fast and highly reproducible, with kinetics that can be described by a compact model, whereas adding trace oxygen leads to suppre开博体育ssed nucleation and slower/incomplete growth. Oxygen affects graphene quality as assessed by surface contamination, emergence of the Raman D peak and decrease in electrical conductivity. Epitaxial graphene grown in oxygen-free conditions is contamination-free and shows no detectable D peak. After dry transfer and boron nitride encapsulation, it shows room-temperature electrical-transport behaviour close to that of exfoliated graphene. A graphite-gated device shows well-developed integer and fractional quantum Hall effects. By highlighting the importance of eliminating trace oxygen, this work provides guidance for future CVD system design and operation. The increased reproducibility and quality afforded by OF-CVD synthesis will broadly influence basic research and applications of graphene.
Work hardening in colloidal crystals
胶体晶体的加工硬化
▲ 作者：Seongsoo Kim, Ilya Svetlizky, David A. Weitz Frans Spaepen
▲ 链接：
https://www.nature.com/articles/s41586-024-07453-6
▲ 摘要：
胶体晶体表示出有趣的特征，在很多方面与它们的原子对应物类似。它们具有不异的晶体布局，履历不异的相变，并具有不异的晶体缺点。研究者们发现硬球胶体晶体表示出加工硬化。另外，虽然它们很柔嫩，但胶体晶体的抗剪强度可以增添并接近晶体的理论极限，这是迄今为止很少有其他材料到达的值。
他们利用共聚焦显微镜显示，胶体晶体的强度跟着位错密度的增添而增添，并终究到达原子材料的经典泰勒缩放行动，虽然硬球彼此感化缺少原子彼此感化的复杂性。
研究证实了泰勒硬化是经由过程位错结的构成而发生的。但是，泰勒硬化机制仅在瞬态阶段以后才成立起来，当胶体晶体变得如斯坚固，以致在应变被定位在一个薄的鸿沟层内时，它就住手了，在这个鸿沟层中，滑移是由位错的很是规活动引发的。虽然胶体晶体和原子晶体在粒度和剪切模量上有很多数目级的差别，但它们之间惊人的类似注解加工硬化的遍及性。
▲ Abstract：
Colloidal crystals exhibit interesting properties that are in many ways analogous to their atomic counterparts. They have the same crystal structures, undergo. Here we show that hard-sphere colloidal crystals exhibit work hardening. Moreover, despite their softness, the shear strength of colloidal crystals can increase and approach the theoretical limit for crystals, a value reached in very few other materials so far. We use confocal microscopy to show that the strength of colloidal crystals increases with dislocation density, and ultimately reaches the classic Taylor scaling behaviour for atomic materials, although hard-sphere interactions lack the complexity of atomic interactions. We demonstrate that Taylor hardening arises through the formation of dislocation junctions. The Taylor hardening regime, however, is established only after a transient phase, and it ceases when the colloidal crystals become so hard that the strain is localized within a thin boundary layer in which slip results from an unconventional motion of dislocations. The striking resemblance between colloidal and atomic crystals, despite the many orders of magnitude difference in particle size and shear modulus, demonstrates the universality of work hardening.
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