Multiple softening -vectors driving a cascade of charge density wave phases in VSe2
學年 115
學期 1
出版（發表）日期 2026-10-07
作品名稱 Multiple softening -vectors driving a cascade of charge density wave phases in VSe2
作品名稱（其他語言）
著者 Zheng-Hong Li, Yung-Ting Lee, Cheng-Tien Chiang, Yu-Chan Tai, Chien-Cheng Kuo, Meng-Kai Lin, Chun-Liang Lin, Hung-Chung Hsueh (薛宏中), Ming-Chiang Chung, Chi-Cheng Lee, & Po-Tuan Chen
單位
出版者
著錄名稱、卷期、頁數 Materials Today Physics
摘要 Charge density wave (CDW) formation in low-dimensional materials is commonly attributed to a single dominant phonon instability. Here, using first-principles electronic and phonon calculations, we show that monolayer 1T-VSe2 instead evolves through a cascade of competing metastable phonon instabilities. The pristine phase exhibits multiple unstable phonon modes that generate the sqrt(3)×sqrt(7), sqrt(3)×4, and 4 × 1 CDW phases. Iterative phonon analyses reveal that several of these intermediate states remain dynamically unstable and further relax into larger superstructures, including the newly identified 2sqrt(3)×4 and 2sqrt(3)×8 phases. Distinct phonon-softening pathways are found to converge toward nearly degenerate low-energy CDW configurations, revealing an interconnected energy landscape of competing metastable states. The exceptionally small energy differences among these phases indicate that different CDW sequences can occur under specific experimental conditions, although strain, substrate, and finite temperature effects also play a role. Our results establish a unified phonon-driven cascade framework for CDW formation and the hierarchy of sequential lattice instabilities in VSe2.
關鍵字
語言 en
ISSN
期刊性質 國外
收錄於 SCI
產學合作
通訊作者 Yung-Ting Lee, Hung-Chung Hsueh (薛宏中), Ming-Chiang Chung, Chi-Cheng Lee, & Po-Tuan Chen
審稿制度 否
國別 GBR
公開徵稿
出版型式 ,電子版,紙本
SDGS 優質教育