Electronic structure and physical properties of the monolayer Kagome lattice system AV3Sb5 (A = K, Rb, Cs)

• Published in: Current applied physics 2023-10, Vol.54, p.26-30
• Main Authors: Im, Jun-Hee, Kang, Chang-Jong
• Format: Article
• Language: English
• Subjects: Charge density wave; Density functional theory; Electronic structure; First-principle calculation; Two-dimensional system
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2023.08.001

In this study, we employ density functional theory to investigate the electronic structure and physical properties of the monolayer Kagome lattice system of AV3Sb5 (A = K, Rb, Cs). Our results reveal that charge density wave (CDW) states are present not only in the bulk, but also in the monolayer systems. Notably, we find that the monolayer system exhibits a higher stability of the CDW states compared to the corresponding bulk system. Additionally, we find that external pressure can induce the instability of the CDW states, driving the pristine structure to a stable phase. Our band unfolding and phonon calculations also provide additional support for these findings. Our study suggests that manipulating the dimensions of Kagome lattice materials as well as applying external pressure can lead to desired physical properties, thereby paving the way for material design advancements in the family of AV3Sb5 Kagome lattice systems. [Display omitted] •The Kagome monolayer system of AV3Sb5 (A = K, Rb, Cs) exhibits two distinct charge density wave phases similar to those observed in the bulk system.•In the monolayer system of AV3Sb5, an electronic instability related to the CDW phases leads to imaginary phonon softening at the M point.•The CDW phases are suppressed under pressure in the monolayer system of AV3Sb5.