arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.09482cond-mat.mes-hallphysics.optics
收藏

低角度扭曲双层石墨烯的晶格动力学局域化

Lattice dynamics localization in low-angle twisted bilayer graphene

Andreij C. Gadelha, Douglas A. A. Ohlberg, Cassiano Rabelo, Eliel G. S. Neto, Thiago L. Vasconcelos, João L. Campos, Jessica S. Lemos, Vinícius Ornelas, Daniel … 展开作者

Andreij C. Gadelha, Douglas A. A. Ohlberg, Cassiano Rabelo, Eliel G. S. Neto, Thiago L. Vasconcelos, João L. Campos, Jessica S. Lemos, Vinícius Ornelas, Daniel Miranda, Rafael Nadas, Fabiano C. Santana, Kenji Watanabe, Takashi Taniguchi, Benoit van Troeye, Michael Lamparski, Vincent Meunier, Viet-Hung Nguyen, Dawid Paszko, Jean-Christophe Charlier, Leonardo C. Campos, Luiz G. Cançado, Gilberto Medeiros-Ribeiro, Ado Jorio

摘要:

双层石墨烯中的两个堆叠晶体网络之间的低扭转角使得能够通过形成周期性域来进行自组织晶格重构。这种超晶格调制振动和电子结构,为电子-声子耦合施加新的规则,并最终观察到强相关性和超导性。本文报道了纳米拉曼光谱仪中光的非弹性光的散射产生的重构扭曲双层石墨烯中晶体超晶格的直接光学图像。由于晶格动力学局域化,使得用可见光观察晶体结构成为可能,图像类似于由应变孤子和拓扑点的存在引起的光谱变化。结果是合理的近自由声子模型和电子计算,突出了孤子和拓扑点的相关性,特别是明显的小扭曲角的结构。我们预计我们的发现将在理解Jahn-Teller效应和电子Cooper配对以及许多其他重要的声子相关效应方面发挥作用,并且它可能有助于表征双电子领域最突出平台中的器件。

英文摘要:

A low twist angle between the two stacked crystal networks in bilayer graphene enables self-organized lattice reconstruction with the formation of a periodic domain. This superlattice modulates the vibrational and electronic structures, imposing new rules for electron-phonon coupling and the eventual observation of strong correlation and superconductivity. Direct optical images of the crystal superlattice in reconstructed twisted bilayer graphene are reported here, generated by the inelastic scattering of light in a nano-Raman spectroscope. The observation of the crystallographic structure with visible light is made possible due to lattice dynamics localization, the images resembling spectral variations caused by the presence of strain solitons and topological points. The results are rationalized by a nearly-free-phonon model and electronic calculations that highlight the relevance of solitons and topological points, particularly pronounced for structures with small twist angles. We anticipate our discovery to play a role in understanding Jahn-Teller effects and electronic Cooper pairing, among many other important phonon-related effects, and it may be useful for characterizing devices in the most prominent platform for the field of twistronics.

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。

↑