论文标题
电荷掺杂的隧道光谱签名和相关的莫特过渡以$α$ -rucl $ {_ 3} $与石墨的接近度
Tunneling spectroscopic signatures of charge doping and associated Mott transition in $α$-RuCl${_3}$ in proximity to graphite
论文作者
论文摘要
分层的Mott绝缘子$α$ -RUCL $ {_ 3} $已被广泛研究为潜在的Kitaev量子型旋转液体候选者。在这里，通过用石墨构建异质结构，我们在几层$α$ -rucl $ {_ 3} $上采用了电子隧道测量，并使用扫描隧道显微镜/光谱法进行了电子隧道测量。在$α$ -rucl $ {_ 3} $层上检测到特征性的隧道光谱，与石墨接近。在与石墨直接接触的单层$α$ -rucl $ {_ 3} $中，观察到了莫特 - 差距方面的不同状态。事实证明，间隙状态与$α$ -rucl $ {_ 3} $和石墨的电子轨道密切相关，并且对界面耦合很敏感，其中假设在异质方面的杂交。缝隙状态也被认为是微弱掺杂$α$ -rucl $ {_ 3} $上层层的费用储层。它表明，弱掺杂效应会导致上层层内的莫特 - 差距大大减少，这表明在这些层中发生了非常规的莫特过渡。结果表明，由$α$ -rucl $ {_ 3} $组成的异质结构和石墨是一个很好的平台，用于调查$α$ -rucl $ {_ 3} $中的掺杂物理。因此，将隧穿进入这种掺杂系统是研究其他绝缘旋转液体候选物的有用探针。
The layered Mott insulator $α$-RuCl${_3}$ has been extensively studied as a potential Kitaev quantum spin liquid candidate. Here, by constructing heterostructures with graphite, we employed electron tunneling measurements on few-layer $α$-RuCl${_3}$ using a scanning tunneling microscopy/spectroscopy. Characteristic tunneling spectra were detected on $α$-RuCl${_3}$ layers in proximity to graphite. In the single-layer $α$-RuCl${_3}$ in direct contact with graphite, distinct states in the Mott-gap regime were observed. The in-gap states are demonstrated to be closely related to the electron orbitals in $α$-RuCl${_3}$ and graphite, and to be sensitive to interfacial coupling, where a hybridization at the heterointerface is hypothesized. The in-gap states are also thought of as a charge reservoir for weakly doping the $α$-RuCl${_3}$ upper-layers. It demonstrated that the weak doping effect causes a considerable decrease in the Mott-gap within the upper-layers, suggesting that an unconventional Mott-transition is occurring in these layers. The results show that the heterostructure comprised of $α$-RuCl${_3}$ and graphite is a good platform for investigating the doping physics in $α$-RuCl${_3}$. Therefore, tunneling into such a doped system is a useful probe for studying otherwise insulating spin-liquid candidates.
