Transition to an excitonic insulator from a two-dimensional conventional insulator
Transition to an excitonic insulator from a two-dimensional conventional insulator
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DOI：
10.1103/physrevb.107.075105
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发表时间：
2023-02
影响因子：
3.7
通讯作者：
E. Manousakis
中科院分区：
文献类型：
--
作者：
E. Manousakis
在本文中，首先，我们给出了一个一般的公式来研究真实的材料中激子绝缘体（EI）的基态和元激发。此外，我们讨论了传统的二维（2D）绝缘体的高强度光照射诱导（虽然短暂）的平衡态。然后，我们提出了各种带结构模型，使我们能够研究从传统的绝缘体的EI在二维材料的介电常数，传统的绝缘体间隙（和化学势），导带和价带的带宽和布拉维晶格晶胞尺寸的函数的过渡。本研究的目标之一是确定这些实验确定的参数的范围，以找到最佳的候选材料来实现激子绝缘体。各种带结构的EI能隙方程的数值解显示了EI能隙函数$\Delta（\vec k）$和零温电子和空穴动量分布在布里渊区的显着和有趣的动量依赖性。最后，我们讨论了这些特征可以通过隧道显微镜来检测
In this paper, first, we present a general formulation to investigate the ground-state and elementary excitations of an excitonic insulator (EI) in real materials. In addition, we discuss the out-of-equilibrium state induced (albeit transiently) by high-intensity light illumination of a conventional two-dimensional (2D) insulator. We then, present various band-structure models which allow us to study the transition from a conventional insulator to an EI in 2D materials as a function of the dielectric constant, the conventional insulator gap (and chemical potential), the bandwidths of the conduction and valence bands and the Bravais lattice unit-cell size. One of the goals of this investigation is to determine which range of these experimentally determined parameters to consider in order to find the best candidate materials to realize the excitonic insulator. The numerical solution to the EI gap equation for various band-structures shows a significant and interesting momentum-dependence of the EI gap function $\Delta(\vec k)$ and of the zero-temperature electron and hole momentum-distribution across the Brillouin zone. Last, we discuss that these features can be detected by tunneling microscopy