Confined Monolayer Ag As a Large Gap 2D Semiconductor and Its Momentum Resolved Excited States.
Woojoo LeeYuanxi WangWei QinHyunsue KimMengke LiuT Nathan NunleyBin FangRinu ManiyaraChengye DongJoshua A RobinsonVincent H CrespiXiaoqin LiAllan H MacDonaldChih-Kang ShihPublished in: Nano letters (2022)
2D materials have intriguing quantum phenomena that are distinctively different from their bulk counterparts. Recently, epitaxially synthesized wafer-scale 2D metals, composed of elemental atoms, are attracting attention not only for their potential applications but also for exotic quantum effects such as superconductivity. By mapping momentum-resolved electronic states using time-resolved and angle-resolved photoemission spectroscopy (ARPES), we reveal that monolayer Ag confined between bilayer graphene and SiC is a large gap (>1 eV) 2D semiconductor, consistent with ab initio GW calculations. The measured valence band dispersion matches the GW quasiparticle band structure. However, the conduction band dispersion shows an anomalously large effective mass of 2.4 m 0 . Possible mechanisms for this large enhancement in the "apparent mass" are discussed.
Keyphrases
- molecular dynamics
- high resolution
- room temperature
- quantum dots
- energy transfer
- monte carlo
- human health
- density functional theory
- working memory
- molecular dynamics simulations
- single cell
- single molecule
- health risk
- visible light
- health risk assessment
- magnetic resonance imaging
- diffusion weighted imaging
- climate change
- mass spectrometry
- carbon nanotubes
- heavy metals
- drinking water