《自然》（20241128出版）一周论文导读

 

编译|李言

Nature, 28 November 2024, Volume 635 Issue 8040

《自然》2024年11月28日，第635卷，8040期

物理学Physics

Learning high-accuracy error decoding for quantum processors

用于量子处理器的高精度错误解码的机器学习

▲ 作者：Johannes Bausch, Andrew W. Senior et al.

▲ 链接：https://www.nature.com/articles/s41586-024-08148-8

▲ 摘要：在此，我们开发了一个基于变压器的循环神经网络，其可以学习解码表面码这一领先的量子纠错代码。对于距离3和距离5的表面码，我们的解码器在来自谷歌的Sycamore量子处理器的真实数据上优于其他最先进的解码器。

在距离升11的情况下，解码器利用软读出和泄漏信息，在具有串扰和泄漏等真实噪声的模拟数据上保持其优势。在近似合成数据上训练后，解码器通过在有限的实验样本上训练来适应更复杂但未知的潜在误差分布。

我们的研究展示了机器学习通过直接从数据中学习超越人类设计算法的能力，突出了机器学习作为量子计算机解码有力竞争者的能力。

▲ Abstract：Here we develop a recurrent, transformer-based neural network that learns to decode the surface code, the leading quantum error-correction code. Our decoder outperforms other state-of-the-art decoders on real-world data from Google’s Sycamore quantum processor for distance-3 and distance-5 surface codes. On distances up to 11, the decoder maintains its advantage on simulated data with realistic noise including cross-talk and leakage, utilizing soft readouts and leakage information. After training on approximate synthetic data, the decoder adapts to the more complex, but unknown, underlying error distribution by training on a limited budget of experimental samples. Our work illustrates the ability of machine learning to go beyond human-designed algorithms by learning from data directly, highlighting machine learning as a strong contender for decoding in quantum computers.

材料科学Material Sciences

Isomeric diammonium passivation for perovskite–organic tandem solar cells

钙钛矿—有机串联太阳能电池的异构体二铵钝化

▲ 作者：Xin Jiang, Shucheng Qin et al.

▲ 链接：https://www.nature.com/articles/s41586-024-08160-y

▲ 摘要：在此，我们开发了一种新的表面钝化剂环己烷1,4-二碘化二铵（CyDAI2），它天然含有两种同分异构结构，在己烷环的同侧或相反侧（分别表示为顺式CyDAI2和反式CyDAI2），这两种异构体表现出完全不同的表面相互作用行为。

顺式CyDAI2钝化处理降低了带隙为1.88 eV的WBG pero-SCs的准费米能级劈裂—开路电压失配，将其Voc提高到1.36 V。将顺式CyDAI2处理的钙钛矿与具有1.27 eV窄带隙的有机活性层结合，构建的单片钙钛矿/有机TSC的PCE为26.4%（经认证为25.7%）。

▲ Abstract：Here we exploit a new surface passivator cyclohexane 1,4-diammonium diiodide (CyDAI2), which naturally contains two isomeric structures with ammonium groups on the same or opposite sides of the hexane ring (denoted as cis-CyDAI2 and trans-CyDAI2, respectively), and the two isomers demonstrate completely different surface interaction behaviours. The cis-CyDAI2 passivation treatment reduces the quasi-Fermi-level splitting–open circuit voltage (Voc) mismatch of the WBG pero-SCs with a bandgap of 1.88 eV and enhanced its Voc to 1.36 V. Combining the cis-CyDAI2-treated perovskite and the organic active layer with a narrow bandgap of 1.27 eV, the constructed monolithic perovskite–organic TSC demonstrates a PCE of 26.4% (certified as 25.7%).

Coherent growth of high-Miller-index facets enhances perovskite solar cells

高米勒指数晶面的共格生长增强钙钛矿太阳能电池

▲ 作者：Shunde Li, Yun Xiao et al.

▲ 链接：https://www.nature.com/articles/s41586-024-08159-5

▲摘要：在此，我们报告了一种通过形成一致的晶界来生产高质量的、微米厚的甲脒基钙钛矿薄膜的有效方法，其中高米勒指数取向的晶粒在稳定的气氛中生长在低米勒指数的取向晶粒上。

制备出的微米厚钙钛矿薄膜增强了晶界和晶粒，具有稳定的材料性能和优异的光电性能。小面积太阳能电池的效率达到了26.1%。1cm2器件和5cm×5cm微型模块的效率分别为24.3%和21.4%。

在稳定的气氛中处理的装置在所有四个季节都具有很高的重现性。封装器件在环境空气中的光和热应力下都表现出优异的长期稳定性。

▲ Abstract：Here we report an effective method for producing high-quality, micron-thick formamidinium-based perovskite films by forming coherent grain boundaries, in which high-Miller-index-oriented grains grow on the low-Miller-index-oriented grains in a stabilized atmosphere. The resulting micron-thick perovskite films, with enhanced grain boundaries and grains, showed stable material properties and outstanding optoelectronic performances. The small-area solar cells achieved efficiencies of 26.1%. The 1cm2 devices and 5cm×5cm mini-modules delivered efficiencies of 24.3% and 21.4%, respectively. The devices processed in a stabilized atmosphere presented a high reproducibility across all four seasons. The encapsulated devices exhibited superior long-term stability under both light and thermal stressors in ambient air.

地球科学Earth Science

Biodiversity impacts of the 2019–2020 Australian megafires

2019—2020年澳大利亚特大火灾对生物多样性的影响

▲ 作者：Don A. Driscoll, Kristina J. Macdonald et al.

▲ 链接：https://www.nature.com/articles/s41586-024-08174-6

▲摘要：我们发现，对植物和动物的最大影响是在过去经常发生火灾或最近发生火灾的地区，以及在广泛燃烧的地区。对严重烧毁地区、保护区外或极端干旱地区的影响也更大。影响包括火灾后生物多样性的下降和增加，热带雨林和哺乳动物的反应最大。

我们的研究结果表明，物种相互作用、分散和就地生存的程度是影响火灾反应的机制。在这些生态系统中建立野火抵御能力取决于减少火灾的复发，包括在经常被烧的地区能够迅速扑灭野火。

保护潮湿的生态系统、扩大保护区和减缓局部干旱也可能有所助益。虽然这些对策可以帮助减轻更频繁的特大火灾的影响，但扭转人为气候变化仍然是迫切的大规模解决方案。

▲ Abstract：We reveal that the largest effects on plants and animals were in areas with frequent or recent past fires and within extensively burnt areas. Areas burnt at high severity, outside protected areas or under extreme drought also had larger effects. The effects included declines and increases after fire, with the largest responses in rainforests and by mammals. Our results implicate species interactions, dispersal and extent of in situ survival as mechanisms underlying fire responses. Building wildfire resilience into these ecosystems depends on reducing fire recurrence, including with rapid wildfire suppression in areas frequently burnt. Defending wet ecosystems, expanding protected areas and considering localized drought could also contribute. While these countermeasures can help mitigate the impacts of more frequent megafires, reversing anthropogenic climate change remains the urgent broad-scale solution.

考古学Archaeology

The rise and transformation of Bronze Age pastoralists in the Caucasus

青铜时代高加索地区牧民的兴起和变革

▲ 作者：Ayshin Ghalichi, Sabine Reinhold et al.

▲ 链接：https://www.nature.com/articles/s41586-024-08113-5

▲摘要：在此，我们展示来自38个考古遗址的131个人的新的全基因组数据，时间横跨6000年。我们发现，中石器时代高加索山脉北部和南部人口之间存在强烈的遗传分化，北部有东部狩猎采集者血统，南部有明显的高加索狩猎采集者血统，并日渐与东部安纳托利亚农民血统混合。

在随后的新石器时代，我们观察到典型的西欧亚草原祖先的形成，并在迈科普文化复合体的技术发展的促进下，加强了山区和草原地区之间的互动。

相比之下，青铜器时代早期和中期的游牧活动和领土扩张高峰具有长期的遗传稳定性。青铜时代晚期标志着基因从多个不同的来源流动的另一个时期，这与草原文化的衰落相吻合，随后是草原血统被高地人口转化和吸收。

▲ Abstract：Here we present new genome-wide data for 131 individuals from 38 archaeological sites spanning 6,000 years. We find a strong genetic differentiation between populations north and south of the Caucasus mountains during the Mesolithic, with Eastern hunter-gatherer ancestry in the north, and a distinct Caucasus hunter-gatherer ancestry with increasing East Anatolian farmer admixture in the south. During the subsequent Eneolithic period, we observe the formation of the characteristic West Eurasian steppe ancestry and heightened interaction between the mountain and steppe regions, facilitated by technological developments of the Maykop cultural complex. By contrast, the peak of pastoralist activities and territorial expansions during the Early and Middle Bronze Age is characterized by long-term genetic stability. The Late Bronze Age marks another period of gene flow from multiple distinct sources that coincides with a decline of steppe cultures, followed by a transformation and absorption of the steppe ancestry into highland populations.

医学Medicine

Rifaximin prophylaxis causes resistance to the last-resort antibiotic daptomycin

利福昔明预防性治疗会引发对终极抗生素达托霉素的耐药性

▲ 作者：Adrianna M. Turner, Lucy Li et al.

▲ 链接：https://www.nature.com/articles/s41586-024-08095-4

▲ 摘要：在此，我们展示了利福昔明是一种用于预防肝病患者的肝性脑病无关的抗生素，在VREfm中引起对达托霉素的交叉耐药性。在利福昔明暴露后，细菌RNA聚合酶内产生的氨基酸变化导致先前未表征的操纵子（prdRAB）上调，从而通过减少抗生素的结合导致细胞膜重塑和对达托霉素的交叉抗性。

具有这些突变的VREfm在全球传播，使其成为耐药性的主要机制。此前，利福昔明被认为在产生抗生素耐药性方面为“低风险”。

我们的研究表明，这种假设是有缺陷的，利福昔明的广泛使用，特别是在肝硬化患者中，可能会影响达托霉素的临床使用，达托霉素是治疗多药耐药病原体的主要最后手段。这些发现表明，抗生素交叉耐药性会破坏旨在保护关键抗生素临床使用的全球战略。

▲ Abstract：Here we show that rifaximin, an unrelated antibiotic used prophylactically to prevent hepatic encephalopathy in patients with liver disease, causes cross-resistance to daptomycin in VREfm. Amino acid changes arising within the bacterial RNA polymerase in response to rifaximin exposure cause upregulation of a previously uncharacterized operon (prdRAB) that leads to cell membrane remodelling and cross-resistance to daptomycin through reduced binding of the antibiotic. VREfm with these mutations are spread globally, making this a major mechanism of resistance. Rifaximin has been considered ‘low risk’ for the development of antibiotic resistance. Our study shows that this assumption is flawed and that widespread rifaximin use, particularly in patients with liver cirrhosis, may be compromising the clinical use of daptomycin, a major last-resort intervention for multidrug-resistant pathogens. These findings demonstrate how unanticipated antibiotic cross-resistance can undermine global strategies designed to preserve the clinical use of critical antibiotics.

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