Intercalating Architecture for the Design of Charge Density Wave in Metallic MA2Z4 Materials

Nano Lett. 2024 Sep 11;24(36):11279-11285. doi: 10.1021/acs.nanolett.4c02998. Epub 2024 Aug 15.

Abstract

We present a novel approach to induce charge density waves (CDWs) in metallic MA2Z4 materials, resembling the behavior observed in transition metal dichalcogenides (TMDCs). This method leverages the intercalating architecture to maintain the same crystal field and Fermi surface topologies. Our investigation reveals that CDW instability in these materials arises from electron-phonon coupling (EPC) between the d band and longitudinal acoustic (LA) phonons, mirroring TMDC's behavior. By combining α-MA2Z4 with 1H-MX2 materials in a predictive CDW phase diagram using critical EPC constants, we demonstrate the feasibility of extending CDW across material families with comparable crystal fields and reveal the crucial role in CDW instability of the competition between ionic charge transfer and electron correlation. We further uncover a strain-induced Mott transition in β2-NbGe2N4 monolayer featuring star-of-David patterns. This work highlights the potential of intercalating architecture to engineer CDW materials, expanding our understanding of CDW instability and correlation physics.

Keywords: Charge Density Wave; Intercalating Architecture Approach; MA2Z4 Materials; Mott Transition; Phase Diagram; Star of David.