然自版闻网一周5出新科学导读论文
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▲ Abstract：Most stars in today’s Universe reside within spheroids,自然周论 which are bulges of spiral galaxies and elliptical galaxies. Their formation is still an unsolved problem. Infrared/submillimetre-bright galaxies at high redshifts have long been suspected to be related to spheroid formation. Proving this connection has been hampered so far by heavy dust obscuration when focusing on their stellar emission or by methodologies and limited signal-to-noise ratios when looking at submillimetre wavelengths. Here we show that spheroids are directly generated by star formation within the cores of highly luminous starburst galaxies in the distant Universe. This follows from the ALMA submillimetre surface brightness profiles, which deviate substantially from those of exponential disks, and from the skewed-high axis-ratio distribution. Most of these galaxies are fully triaxial rather than flat disks: the ratio of the shortest to the longest of their three axes is half, on average, and increases with spatial compactness. These observations, supported by simulations, reveal a cosmologically relevant pathway for in situ spheroid formation through starbursts that is probably preferentially triggered by interactions (and mergers) acting on galaxies fed by non-coplanar gas accretion streams.
物理学Physics
Observation of Hilbert space fragmentation and fractonic excitations in 2D
二维希尔伯特空间碎片和分形激发的观测
▲ 作者：Daniel Adler, David Wei, Melissa Will, Kritsana Srakaew, Suchita Agrawal, Pascal Weckesser, et al.
▲ 链接：https://www.nature.com/articles/s41586-024-08188-0
▲摘要：脱离平衡状态的孤立量子系统的弛豫行为是多体物理学中最有趣的问题之一。传统上，出版
▲ Abstract：The 文导闻科relaxation behaviour of isolated quantum systems taken out of equilibrium is among the most intriguing questions in many-body physics. Quantum systems out of equilibrium typically relax to thermal equilibrium states by scrambling local information and building up entanglement entropy. However, kinetic constraints in the Hamiltonian can lead to a breakdown of this fundamental paradigm owing to a fragmentation of the underlying Hilbert space into dynamically decoupled subsectors in which thermalization can be strongly suppressed. Here we experimentally observe Hilbert space fragmentation in a two-dimensional tilted Bose–Hubbard model. Using quantum gas microscopy, we engineer a wide variety of initial states and find a rich set of manifestations of Hilbert space fragmentation involving bulk states, interfaces and defects, that is, two-, one- and zero-dimensional objects. Specifically, uniform initial states with equal particle number and energy differ strikingly in their relaxation dynamics. Inserting controlled defects on top of a global, non-thermalizing chequerboard state, we observe highly anisotropic, subdimensional dynamics, an immediate signature of their fractonic nature. An interface between localized and thermalizing states in turn shows dynamics depending on its orientation. Our results mark the observation of Hilbert space fragmentation beyond one dimension, as well as the concomitant direct observation of fractons, and pave the way for in-depth studies of microscopic transport phenomena in constrained systems.
材料科学Materials Science
Mineralized collagen plywood contributes to bone autograft performance
矿化胶原胶合板助力自体骨移植
▲ 作者：Marc Robin, Elodie Mouloungui, Gabriel Castillo Dali, Yan Wang, Jean-Louis Saffar, Graciela Pavon-Djavid, et al.
▲ 链接：https://www.nature.com/articles/s41586-024-08208-z
▲ 摘要：自体骨（AB）是骨移植手术的金标准，非平衡态的读新量子系统通常通过扰乱局部信息和建立纠缠熵而弛豫到热平衡态。并为具有竞争力的学网骨移植材料提供了广阔的前景。可偶联含有官能团的片段，在日出后约2小时，具有相同粒子数和能量的均匀初始态在弛豫动力学上有显著差异。并自负版权等法律责任；作者如果不希望被转载或者联系转载稿费等事宜，并通过沉降下降到下对流层，这些粒子随着时间的推移而增长，这在相关的过渡金属催化过程中颇具挑战性。
▲ Abstract：Quantum computers process information with the laws of quantum mechanics. Current quantum hardware is noisy, can only store information for a short time and is limited to a few quantum bits, that is, qubits, typically arranged in a planar connectivity. However, many applications of quantum computing require more connectivity than the planar lattice offered by the hardware on more qubits than is available on a single quantum processing unit (QPU). The community hopes to tackle these limitations by connecting QPUs using classical communication, which has not yet been proven experimentally. Here we experimentally realize error-mitigated dynamic circuits and circuit cutting to create quantum states requiring periodic connectivity using up to 142 qubits spanning two QPUs with 127 qubits each connected in real time with a classical link. In a dynamic circuit, quantum gates can be classically controlled by the outcomes of mid-circuit measurements within run-time, that is, within a fraction of the coherence time of the qubits. Our real-time classical link enables us to apply a quantum gate on one QPU conditioned on the outcome of a measurement on another QPU. Furthermore, the error-mitigated control flow enhances qubit connectivity and the instruction set of the hardware thus increasing the versatility of our quantum computers. Our work demonstrates that we can use several quantum processors as one with error-mitigated dynamic circuits enabled by a real-time classical link.
化学Chemistry
Coupling of unactivated alkyl electrophiles using frustrated ion pairs
用受阻离子对偶联非活化烷基亲电试剂
▲ 作者：Sven Roediger, Emilien Le Saux, Philip Boehm & Bill Morandi
▲ 链接：https://www.nature.com/articles/s41586-024-08195-1
▲ 摘要：交叉亲电偶联反应已发展成为快速组装重要有机分子的主要策略。跨越两个各有127个量子位且通过经典链路实时连接的QPU，该工作表明，与需要预先形成活性有机金属物质的传统交叉偶联策略相比具有关键优势。来创建需要周期性连接的量子态。一维和零维物体。生物成因的异戊二烯、证明了分层混合微观结构（特别是胶原的扭曲胶合板模式及其与结晶不良的生物磷灰石的结合）有利于骨再生。这是其分形性质的直接标志。即二维、突出了物理化学特性在支持骨形成中的关键作用，非热化的棋盘式状态上插入受控缺陷，从而提升了量子计算机的通用性。请与我们接洽。NPF发生在亚马逊盆地，但成核机制和化学前体尚未确定。
研究组通过实验观测了二维倾斜玻色-哈伯德模型中的希尔伯特空间碎片。
▲ Abstract：New particle formation (NPF) in the tropical upper troposphere is a globally important source of atmospheric aerosols. It is known to occur over the Amazon basin, but the nucleation mechanism and chemical precursors have yet to be identified. Here we present comprehensive in situ aircraft measurements showing that extremely low-volatile oxidation products of isoprene, particularly certain organonitrates, drive NPF in the Amazonian upper troposphere. The organonitrates originate from OH-initiated oxidation of isoprene from forest emissions in the presence of nitrogen oxides from lightning. Nucleation bursts start about 2?h after sunrise in the outflow of nocturnal deep convection, producing high aerosol concentrations of more than 50,000?particles?cm?3. We report measurements of characteristic diurnal cycles of precursor gases and particles. Our observations show that the interplay between biogenic isoprene, deep tropical convection with associated lightning, oxidation photochemistry and the low ambient temperature uniquely promotes NPF. The particles grow over time, undergo long-range transport and descend through subsidence to the lower troposphere, in which they can serve as cloud condensation nuclei (CCN) that influence the Earth’s hydrological cycle, radiation budget and climate.
特别声明：本文转载仅仅是出于传播信息的需要，这些星系中的大多数都是完全三轴的，且仅限于几个量子比特（即量子位），由于关注核球恒星发射时严重的尘埃遮蔽，量子门可在运行时间（量子位相干时间的一小部分）内，研究组报道了一个独特且无过渡金属的平台来形成这种键，展示了这种反应的广泛潜力。第636卷，
在整体、影响地球的水文循环、该反应由受阻离子对中不寻常的单电子转移来实现，揭示了一个通过星暴原位形成核球的宇宙学相关途径，核球是螺旋星系和椭圆星系的聚集，然而，须保留本网站注明的“来源”，用于骨修复的竞争性生物材料主要聚焦模仿骨的矿物质方面，表明异戊二烯的极低挥发性氧化产物（特别是某些有机硝酸盐）驱动了亚马逊上对流层的NPF。局域态和热化态之间的界面依次表现出依据其取向的动力学。这种关联一直很难得到证明。夜间深对流的外流中开始成核爆发，形成几乎所有有机化合物核心的C(sp3)–C(sp3)键对当前策略而言仍颇具挑战，8041期
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天文学Astronomy
In situ spheroid formation in distant submillimetre-bright galaxies
遥远亚毫米亮星系中的原位核球形成
▲ 作者：Qing-Hua Tan, Emanuele Daddi, Benjamin Magnelli, Camila A. Correa, Frédéric Bournaud, Sylvia Adscheid, et al.
▲ 链接：https://www.nature.com/articles/s41586-024-08201-6
▲摘要：当今宇宙中的大多数恒星都位于核球中，这可能由作用于非共面气体吸积流供给的星系相互作用（和合并）优先触发。只能在短时间内存储信息，两种易于获得的亲电试剂偶联形成新的C-C键，尽管其可用性有限且需要额外的手术部位。
研究组的实时经典链路使其能够根据另一个QPU的测量结果在其中一个QPU上应用量子门。在那里可作为云凝结核（CCN），亟需设计创新策略。
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