Fast two-dimensional long-wavelength plasmons in atomically thin MoS2
學年 114
學期 2
出版（發表）日期 2026-04-24
作品名稱 Fast two-dimensional long-wavelength plasmons in atomically thin MoS2
作品名稱（其他語言）
著者 Chien-Ting Wu, Chih-En Hsu, Chih-Ying Huang, Yung-Ning Hsu, Che-Lun Lee, Ssu-Yen Huang, Chun-Wei Chen, Hung-Chung Hsueh,* and Ming-Wen Chu
單位
出版者
著錄名稱、卷期、頁數 PHYSICAL REVIEW RESEARCH, vol. 8, p. 023072
摘要 Plasmons are bosonic wavelike charge oscillations in solids and the plasmon group velocity (𝑣g), the first derivative of momentum (𝑞)-dependent dispersions, depicts the many-body electron motions of critical electronic importance. The profound characteristics of 𝑣g in either three-dimensional (3D) or two-dimensional (2D) electron systems are nonetheless short of quantitative scrutiny. Using 𝑞-resolved electron energy loss spectroscopy, we tackle the 𝑞-dependent 𝑣g of π and π + σ plasmons in 3D-bulk and 2D-monolayer (ML) Mo⁢S2 semiconductors, with the 2D Mo⁢S2 being the model transition-metal dichalcogenide (TMD) for emergent atomically thin electronics. 𝑣g along with the underlining electronic parameters of the charge density, effective mass, and screening length in 2D for the plasmon dispersions is quantitatively elaborated. 2D 𝑣g is further compared to those evaluated from metallic ML-TMD Ta⁢S2 and graphene, and the scaling over the single-particle Fermi velocity (𝑣F) unveils a 𝑣g/𝑣F function generally obeyed by the semiconducting and metallic TMD and graphene of distinctly different massive and relativistic characters, respectively. Beyond the pertinent critical 𝑞 (on the order of 10−2Å−1) where one observes 𝑣g=𝑣F, electric-field lines connecting the oscillating 2D charges would turn from vacuum into the atomically thin matters, concomitant with the increasing plasmon damping and reducing 𝑣g (𝑣g<𝑣F). Long-wavelength 2D plasmons below the critical 𝑞 characterize the field lines largely in vacuum and are persistent and fast (𝑣g>𝑣F), with high-speed application merits. Conversely, 3D plasmons in bulk Mo⁢S2 never exceed 𝑣F.
關鍵字
語言 zh_TW
ISSN
期刊性質 國外
收錄於 SCI
產學合作
通訊作者 Hung Chung Hsueh, MIng-Wen Chu
審稿制度 1
國別 USA
公開徵稿
出版型式 ,電子版,紙本
SDGS 優質教育