arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2007.11128cond-mat.str-elcond-mat.mes-hall
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WSe $_{2}$ / WS $_{2}$莫尔超晶格中分数填充时相关绝缘态的消除

Abundance of correlated insulating states at fractional fillings of WSe$_{2}$/WS$_{2}$ moiré superlattices

Yang Xu, Song Liu, Daniel A Rhodes, Kenji Watanabe, Takashi Taniguchi, James Hone, Veit Elser, Kin Fai Mak, Jie Shan

摘要:

在物理学中,晶格上具有竞争性长程相互作用的量子粒子无处不在。过渡金属氧化物、层状分子晶体和捕获离子阵列是许多例子中的几个。在强相互作用体系中,这些系统经常表现出丰富多样的量子多体基态,这对理论提出了挑战。过渡金属二硫属化物云纹异质结构的出现为研究长程电子关联提供了一个高度可控的平台。在这里,我们报告了近二十打的相关绝缘状态的观察在分数填充的WSe $_{2}$ /WS $_{2}$莫尔异质结构。这一发现是通过一种新的光学传感技术实现的,该技术是建立在对单层半导体WSe $_{2}$中激子激发态的介电环境的敏感性上的。绝缘态的级联表现出一种能量有序性,这种有序性关于每个超晶格位置的半个电子(或空穴)的填充因子几乎是对称的。我们提出了一系列的电荷有序状态在相称的填充分数,范围从广义维格纳晶体的电荷密度波。我们的研究为利用莫尔超晶格模拟大量的量子多体问题奠定了基础,这些问题由二维t-V模型或具有长程电荷-电荷和交换相互作用的自旋模型描述。

英文摘要:

Quantum particles on a lattice with competing long-range interactions are ubiquitous in physics. Transition metal oxides, layered molecular crystals and trapped ion arrays are a few examples out of many. In the strongly interacting regime, these systems often exhibit a rich variety of quantum many-body ground states that challenge theory. The emergence of transition metal dichalcogenide moiré heterostructures provides a highly controllable platform to study long-range electronic correlations. Here we report an observation of nearly two-dozen correlated insulating states at fractional fillings of a WSe$_{2}$/WS$_{2}$ moiré heterostructure. The discovery is enabled by a new optical sensing technique that is built on the sensitivity to dielectric environment of the exciton excited states in single-layer semiconductor WSe$_{2}$. The cascade of insulating states exhibits an energy ordering which is nearly symmetric about filling factor of half electron (or hole) per superlattice site. We propose a series of charge-ordered states at commensurate filling fractions that range from generalized Wigner crystals to charge density waves. Our study lays the groundwork for utilizing moiré superlattices to simulate a wealth of quantum many-body problems that are described by the two-dimensional t-V model or spin models with long-range charge-charge and exchange interactions.

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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