论文标题
部分可观测时空混沌系统的无模型预测
Dynamics of ethylene groups and hyperfine interactions between donor and anion molecules in $λ$-type organic conductors studied by $^{69,71}$Ga-NMR spectroscopy
论文作者
论文摘要
我们介绍了有机抗firomagnet $λ$ - （bedse-ttf）$^{69,71} $ ga-nmr测量结果[BETS = BIS（Ethylenedithio）Tetraselenafulvalene] [T。 Kobayashi等人，物理。 Rev. B 102，235131（2020）]。我们发现，两个晶体独立的乙烯基的动力学在高温区域诱导了两种类型的四极松弛。随着乙烯运动的冻结，超精细（HF）相互作用在$π$ spin和GA核自旋之间发展，从而从GA位点检测到$π$ -SPIN系统的磁波动。 $λ$ - （下注）$ _ 2 $ gacl $ _4 $的HF互动大于$λ$ - （bedse-ttf）$ _ 2 $ gacl $ _4 $的两倍，这意味着Cl Atoms和Fulvalene Parts of Fulvalene parts of Fulvalene parts of Fulvalene Part之间的短触点对于转移HF互动是必不可少的。我们提出，在阴离子层中使用核的NMR可用于研究有机导体中层间相互作用，这些相互作用尚未通过实验研究。此外，由于转移的HF相互作用的机制被认为与$π$ - $ d $ $ d $相同的相互作用在含有$λ$ - 型盐中的相互作用，因此我们的发现有助于理解其物理性质。
We present the results of $^{69,71}$Ga-NMR measurements on an organic antiferromagnet $λ$-(BEDSe-TTF)$_2$GaCl$_4$ [BEDSe-TTF=bis(ethylenediseleno)tetrathiafulvalene], with comparison to reports on $λ$-(BETS)$_2$GaCl$_4$ [BETS=bis(ethylenedithio)tetraselenafulvalene] [T. Kobayashi et al., Phys. Rev. B 102, 235131 (2020)]. We found that the dynamics of two crystallographically independent ethylene groups induce two types of quadrupolar relaxation in the high-temperature region. As the ethylene motion freezes, hyperfine (HF) interactions develop between $π$ spin and Ga nuclear spin below 100 K, and thereby magnetic fluctuations of the $π$-spin system are detected even from the Ga site. The HF interaction in $λ$-(BETS)$_2$GaCl$_4$ was more than twice as large as in $λ$-(BEDSe-TTF)$_2$GaCl$_4$, implying that the short contacts between Cl atoms and the chalcogens of fulvalene part are essential for the transferred HF interaction. We propose that NMR using nuclei in anion layers is useful for studying interlayer interactions in organic conductors, which have not been studied experimentally. In addition, because the mechanism of the transferred HF interaction is considered to be the same as $π$-$d$ interaction in isostructural Fe-containing $λ$-type salts, our findings aid in the understanding of their physical properties.
