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arXiv 2302.14072cond-mat.str-elcond-mat.mes-hallcond-mat.mtrl-sci
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异质Ta-二硫族化物双层:重费米子还是掺杂莫特物理?

Heterogeneous Ta-dichalcogenide bilayer: heavy fermions or doped Mott physics?

Lorenzo Crippa, Hyeonhu Bae, Paul Wunderlich, Igor I. Mazin, Binghai Yan, Giorgio Sangiovanni, Tim Wehling, Roser Valentí

AI总结:

基于第一性原理计算,本文重新解释了Ta-二硫族化物双层异质结构,发现其电子从1T层向1H层发生显著电荷转移,系统更接近掺杂莫特绝缘体而非重费米子,为量子材料工程提供了新平台。

摘要:

控制和理解量子物质中的电子关联是材料工程中最具挑战性的任务之一。近年来,通过仔细堆叠和扭转不同种类的二维范德华材料,发现了大量令人困惑的新关联态。这些堆叠结构的独特之处在于出现了单层无法预见的关联相。在由良好金属1H层和莫特绝缘体1T层构成的Ta-二硫族化物异质结构中,最近的报告证明了电子激发具有巡游和局域的混合特性,类似于重费米子系统中常见的现象。在此,我们基于第一性原理计算提出了一种新解释,表明在层间距离增大的情况下,电子从1T层向1H层发生了显著的电荷转移(0.4-0.6 e)。我们精确量化了层间杂化的强度,使我们能够明确判定该系统更接近于掺杂莫特绝缘体,而非重费米子情形。因此,Ta基异质层为量子材料工程提供了一个新平台,即在范德华距离下与金属态杂化的重掺杂莫特绝缘体领域。

英文摘要:

Controlling and understanding electron correlations in quantum matter is one of the most challenging tasks in materials engineering. In the past years a plethora of new puzzling correlated states have been found by carefully stacking and twisting two-dimensional van der Waals materials of different kind. Unique to these stacked structures is the emergence of correlated phases not foreseeable from the single layers alone. In Ta-dichalcogenide heterostructures made of a good metallic 1H- and a Mott-insulating 1T-layer, recent reports have evidenced a cross-breed itinerant and localized nature of the electronic excitations, similar to what is typically found in heavy fermion systems. Here, we put forward a new interpretation based on first-principles calculations which indicates a sizeable charge transfer of electrons (0.4-0.6 e) from 1T to 1H layers at an elevated interlayer distance. We accurately quantify the strength of the interlayer hybridization which allows us to unambiguously determine that the system is much closer to a doped Mott insulator than to a heavy fermion scenario. Ta-based heterolayers provide therefore a new ground for quantum-materials engineering in the regime of heavily doped Mott insulators hybridized with metallic states at a van der Waals distance.

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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