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arXiv 2301.09658cond-mat.mes-hallcond-mat.str-el
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Moiré TMD 双层中的表观近藤效应:重费米子还是无序?

Apparent Kondo effect in Moiré TMD bilayers: Heavy fermions or disorder?

Prathyush P. Poduval, Katharina Laubscher, Sankar Das Sarma

AI总结:

本文质疑 Moiré TMD 双层中近藤晶格的形成,提出杂质与声子散射可替代解释实验观测的电阻率平台和质量增强,指出需进一步验证重费米子图像。

摘要:

Zhao 等人最近的一项工作[1]报告了在栅极可调的 Moiré TMD 双层系统中实现了合成近藤晶格。观测到近藤晶格的依据是:电阻率 $ρ(T)$ 的温度依赖性在 $T^*\sim 40$ K 附近出现平台(或凹陷,取决于填充),这被解释为近藤温度尺度;以及从低温电阻率数据中提取的载流子质量明显增强,表明出现了“重费米子”。后一项观测关键依赖于一个假设,即主要的电阻散射机制是底层费米液体中的 Umklapp 电子-电子散射。在本工作中,我们在另一种假设下分析实验数据,即主要电阻散射机制不是电子-电子散射,而是随机淬灭带电杂质引起的库仑散射和声子散射。我们表明,杂质散射和声子散射的组合是对观测到的电阻率的一种合理的替代解释,即使没有形成近藤晶格,也能描述实验数据的关键特征,这表明需要进一步的理论和实验工作来确证文献[1]中近藤晶格的形成。\n[1] W. Zhao, B. Shen, Z. Tao, Z. Han, K. Kang, K. Watanabe, T. Taniguchi, K. F. Mak, and J. Shan, arXiv:2211.00263 (2022).

英文摘要:

A recent work by Zhao et al. [1] reports the realization of a synthetic Kondo lattice in a gate-tunable Moiré TMD bilayer system. The observation of a Kondo lattice is supported by a plateau (or dip, depending on filling) in the temperature dependence of the resistivity $ρ(T)$ around $T^*\sim 40~$K, which is interpreted as the Kondo temperature scale, and an apparent enhancement of carrier mass extracted from the low-temperature resistivity data, indicating the emergence of `heavy fermions'. The latter observation is crucially based on the assumption that the primary resistive scattering mechanism is Umklapp electron-electron scattering in the underlying Fermi liquid. In this work, we analyze the experimental data under the assumption that the primary resistive scattering mechanism is not electron-electron scattering, but Coulomb scattering by random quenched charged impurities and phonon scattering. We show that a combination of impurity and phonon scattering is a plausible alternative explanation for the observed resistivity that can describe the key features of the experimental data, even if no Kondo lattice has formed, indicating that further theoretical and experimental work is needed to conclusively verify the formation of a Kondo lattice in Ref. [1]. [1] W. Zhao, B. Shen, Z. Tao, Z. Han, K. Kang, K. Watanabe, T. Taniguchi, K. F. Mak, and J. Shan, arXiv:2211.00263 (2022).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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