石墨烯和拓扑绝缘体中极化子态的基本性质研究

项目名称： 石墨烯和拓扑绝缘体中极化子态的基本性质研究

项目编号： No.11464033

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 丁朝华

作者单位： 内蒙古民族大学

项目金额： 50万元

中文摘要： 近些年发现的新型材料体系-石墨烯和拓扑绝缘体，由于其奇特而新颖的物理特性迅速成为凝聚态物理研究的热点。在这些材料体系中电子与声子的相互作用导致了电子与声子耦合整体的准粒子态形成，即极化子。这种极化子态对充分研究材料体系中的电子与声子耦合强度、光的吸收和发射、热散射输运及超导本质等是非常重要的。本课题拟针对这两种新型材料，利用线性组合算符方法对多种极化子态进行系统的研究。我们将重点讨论极化子效应导致的费米能级修正、石墨烯带隙的分开。同时，结合费米黄金规则，基于光学声子的发射，对光学极化子的寿命也进行深入的研究。另一方面，就外界温度、电子-声子耦合强度、形变势常数、电磁场等因素对极化子态的影响也将进行着重讨论。结合当前的这方面研究的实验数据，对理论结果进行系统分析，以达到对石墨烯和拓扑绝缘体中极化子效应的全面认识。

中文关键词： 石墨烯；拓扑绝缘体；极化子；极化子寿命；线性组合算符

英文摘要： In recent years, the appearing of novel low-dimensional materials graphene and topological insulator quickly become the hot spots in condense matter physical field due to its many peculiar properties. The quasi-particle states are formed arising from the interactions between the electron and phonon, that is the polaron, which is very important to study the strength of electron-phonon coupling, the emission and absorption of light, thermal transport, the original of superconductor and so on. In this project, we mainly investigate the effects of the polaron in the graphene and topological insulator system by using the linear combination operator method. We will mainly the renormalization of the Fermi velocity and the gap opening mechanism for the graphene. Meanwhile, the optical polaron time will also discuss in the emission of optical phonon mechanism based on the Fermi's golden rule. On the other hand, we also study the influences of the temperature, the strength of electron-phonon coupling, the constant of deformation potential and the electrical and magnetic field on the properties of polaron and polaron time. Through the comparisons between our theoretical results and the existed experimental date, we can understand and masterthe basic properties of polaron effects in graphene and topological insulator further.

英文关键词： graphene;topological insulator;polaron;polaron time;linear combination operator method