《科学》（20240920出版）一周论文导读

 
《科学》（20240920出版）一周论文导读  
 

编译|冯维维

Science,  VOLUME 385,ISSUE 6715,20 SEP 2024

《科学》第385卷，6715期，2024年9月20日

物理学Physics

Squeezing the quantum noise of a gravitational-wave detector below the standard quantum limit

将引力波探测器的量子噪声压缩到标准量子极限以下

▲ 作者：WENXUAN JIA , VICTORIA XU , KEVIN KUNS, MASAYUKI NAKANO, LISA BARSOTTI, MATTHEW EVANS, NERGIS MAVALVALA, AND MEMBERS OF THE LIGO SCIENTIFIC COLLABORATION

▲链接：

https://www.science.org/doi/10.1126/science.ado8069

▲摘要：

引力波探测器使用数公里长的干涉仪来测量时空的微小膨胀和收缩。由于量子力学的原因，这些测量的精度是有限的。理论上，利用光的压缩态可以超越量子极限，而合适的滤光腔可以在更宽的频率范围内扩展这一优势。

Jia等人测量了激光干涉引力波天文台（LIGO）升级后的压缩光和滤光腔系统的性能。研究证明，这些升级提高了探测器在宽频率范围内的灵敏度。在一个较小的范围内，它超越了量子极限。

▲ Abstract：

Gravitational wave detectors use kilometers-long interferometers to measure tiny expansions and contractions of spacetime. The precision of those measurements is limited due to quantum mechanics. Theoretically, that quantum limit could be surpassed by using squeezed states of light, and a suitable filter cavity could extend the advantage over a wide frequency range. Jia et al. measured the performance of the Laser Interferometer Gravitational-Wave Observatory (LIGO) after it was upgraded with a squeezed light and filter cavity system. The authors demonstrate that the upgrades improved the sensitivity of the detector over a wide range of frequencies. Over a smaller range, it surpassed the quantum limit. 

Origin and fate of the pseudogap in the doped Hubbard model

掺杂哈伯德模型中赝隙的起源和命运

▲ 作者：FEDOR IMKOVIC IV, RICCARDO ROSSI, ANTOINE GEORGES, AND MICHEL FERRERO

▲链接：

https://www.science.org/doi/10.1126/science.ade9194

▲摘要：

尽管它很简约，哈伯德模型却能描述一些强相关物质的实例，但仍有一些在数值上难以解决的问题，将零温度和有限温度下的结果联系起来尤其棘手。

Simkovic等人使用图解蒙特卡罗计算来检查在有限温度下掺杂哈伯德模型中赝隙相的外观。发现该相与反铁磁自旋相关密切相关，并与零温度下计算的基态条纹相相连。

▲ Abstract：

Despite its simplicity, the Hubbard model may be capable of describing some instances of strongly correlated matter. However, this remains difficult to solve numerically; connecting the results at zero and finite temperatures is particularly tricky. Simkovic et al. used diagrammatic Monte Carlo calculations to examine the appearance of the pseudogap phase in the doped Hubbard model at finite temperatures. This phase was found to be closely associated with antiferromagnetic spin correlations and to connect to the ground-state stripe phase calculated at zero temperature. 

化学Chemistry

Polyolefin waste to light olefins with ethylene and base-metal heterogeneous catalysts

用乙烯和贱金属非均相催化剂将废旧聚烯烃转化为轻烯烃

▲ 作者：RICHARD J. CONK, JULES F. STAHLER, JAKE X. SHI, JI YANG, NATALIE G. LEFTON, JOHN N. BRUNN, ALEXIS T. BELL, AND JOHN F. HARTWIG

▲链接：

https://www.science.org/doi/10.1126/science.adq7316

▲摘要：

原则上，将塑料分解成其原始构件是一种理想的回收策略。但在实践中，这种方法不可能用于目前使用的两种最常见的塑料——聚乙烯和聚丙烯。因为相关反应在能耗上不占优势。最近，几组研究人员表明，用合适的催化剂引入新鲜的乙烯可以将聚烯烃转化为丙烯，但用于催化的贵金属价格过高。

现在Conk等人发现，可以在这个过程中使用地球上更丰富的氧化钨和钠的组合。研究表明，氧化钨在二氧化硅上和钠在γ-氧化铝上的简单组合将聚乙烯和聚丙烯或两者的混合物转化为丙烯或丙烯和异丁烯的混合物，在320°C下产量大于90%，而不需要对起始聚烯烃进行脱氢。

▲ Abstract：