Theory of Exciton-Exciton Interactions in Monolayer Transition Metal Dichalcogenides
Theory of Exciton-Exciton Interactions in Monolayer Transition Metal Dichalcogenides
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DOI：
10.1002/pssb.201800185
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发表时间：
2018-12-01
影响因子：
1.6
通讯作者：
Knorr, Andreas
中科院分区：
文献类型：
--
作者：
Katsch, Florian;Selig, Malte;Knorr, Andreas
过渡金属二硫属化物（TMDC）的二维层表示具有复杂的单粒子能带结构的半导体，并减少三维库仑相互作用的屏蔽。有效的库仑相互作用导致靠近带边的光学激发由强关联的束缚电子-空穴对（称为激子）主导。在这里，提出了一种理论形式主义，有效地描述原子薄TMDC的光学动力学在一个自然适应的两粒子激子的基础。作为一个例子，在Hartree-Fock近似下讨论了库仑谷内耦合，谷间交换，以及内禀和类Dexter谷间相互作用。
Two-dimensional layers of transition metal dichalcogenides (TMDCs) represent semiconductors with a complex single-particle bandstructure and reduce screening of the three-dimensional Coulomb interaction. The efficient Coulomb interaction causes optical excitations close to the band edge to be dominated by strongly correlated, bound electron-hole pairs, called excitons. Here, a theoretical formalism is presented to efficiently describe the optical dynamics of atomically thin TMDCs in a naturally adapted two particle exciton basis. As an example, Coulomb intravalley coupling, intervalley exchange, as well as intrinsic and Dexter-like intervalley interactions are discussed in Hartree-Fock approximation.