《自然》（20240808出版）一周论文导读
Nature, 8 August 2024, Volume 632 Issue 8024
《自然》2024年8月8日，第632卷，8024期
?
物理学Physics
Antiferromagnetic phase transition in a 3D fermionic Hubbard model
三维费米子哈伯德模型中的反铁磁相变
▲ 作者：Hou-Ji Shao, Yu-Xuan Wang et al.
▲链接：
https://www.nature.com/articles/s41586-024-07689-2
▲摘要：
费米子哈伯德模型（FHM）描述了由强电子—电子相关性引起的广泛的物理现象，包括非常规超导的推测机制。在此，我们报告了一个由锂-6原子组成的三维费米子哈伯德系统的反铁磁相变的观察，该系统在一个均匀的光学晶格中有大约80万个位点。当相互作用强度、温度和掺杂浓度被微调到接近各自的临界值时，我们观察到自旋结构因子急剧增加。
这些观察结果可以用幂律发散来解释，从海森堡普适性类来看，其临界指数为1.396。在半填充和最佳相互作用强度下，测得的自旋结构因子达到123(8)，表明了反铁磁相的建立。我们的研究结果为探索FHM的低温相图提供了机会。
▲ Abstract：
The fermionic Hubbard model (FHM) describes a wide range of physical phenomena resulting from strong electron–electron correlations, including conjectured mechanisms for unconventional superconductivity. Here we report the observation of the antiferromagnetic phase transition in a three-dimensional fermionic Hubbard system comprising lithium-6 atoms in a uniform optical lattice with approximately 800,000 sites. When the interaction strength, temperature and doping concentration are finely tuned to approach their respective critical values, a sharp increase in the spin structure factor is observed. These observations can be well described by a power-law divergence, with a critical exponent of 1.396 from the Heisenberg universality class. At half-filling and with optimal interaction strength, the measured spin structure factor reaches 123(8), signifying the establishment of an antiferromagnetic phase. Our results provide opportunities for exploring the low-temperature phase diagram of the FHM.
材料科学Materials Science
Water- and heat-activated dynamic passivation for perovskite photovoltaics
钙钛矿光伏电池的水活化和热活化动态钝化
▲ 作者：Wei-Ting Wang, Philippe Holzhey et al.
▲链接：
https://www.nature.com/articles/s41586-024-07705-5
▲摘要：
在此，我们报告了一种使用阻碍脲/硫代氨基甲酸酯键Lewis酸碱材料（HUBLA）的活性钝化策略，其中具有水和热活化特性的动态共价键可以动态修复钙钛矿，以确保设备的性能和稳定性。暴露于湿气或高温下，HUBLA会产生新的试剂，并进一步钝化钙钛矿中的缺陷。
这种钝化策略实现了功率转换效率（PCE）为25.1%的高性能器件。HUBLA设备在85摄氏度的氮气中老化约1500小时后，其初始PCE保持在94%，在85摄氏度和30%相对湿度的空气中老化1000小时后，其初始PCE保持在88%。
▲ Abstract：
Here we report a living passivation strategy using a hindered urea/thiocarbamate bond Lewis acid–base material (HUBLA), where dynamic covalent bonds with water and heat-activated characteristics can dynamically heal the perovskite to ensure device performance and stability. Upon exposure to moisture or heat, HUBLA generates new agents and further passivates defects in the perovskite. This passivation strategy achieved high-performance devices with a power conversion efficiency (PCE) of 25.1 per cent. HUBLA devices retained 94 per cent of their initial PCE for approximately 1,500 hours of ageing at 85 degrees Celsius in nitrogen and maintained 88 per cent of their initial PCE after 1,000 hours of ageing at 85 degrees Celsius and 30 per cent relative humidity in air.
peri-Fused polyaromatic molecular contacts for perovskite solar cells
钙钛矿太阳能电池的聚芳族分子接触
▲ 作者：Ke Zhao, Qingqing Liu et al.
▲链接：
https://www.nature.com/articles/s41586-024-07712-6
▲摘要：
在此，我们报告了一种没有杂原子取代的环绕稠合多环芳烃核心结构，它比传统的杂原子取代核心结构具有更好的载流子传输和选择性。
