石墨烯
太赫兹辐射
等离子体子
光电子学
表面等离子体子
材料科学
物理
凝聚态物理
纳米技术
作者
Baicheng Yao,Yuan Liu,Shu‐Wei Huang,Chanyeol Choi,Zhenda Xie,Jaime Flor Flores,Yu Wu,Mingbin Yu,Dim‐Lee Kwong,Yu Huang,Yunjiang Rao,Xiangfeng Duan,Chee Wei Wong
出处
期刊:Nature Photonics
[Springer Nature]
日期:2017-12-08
卷期号:12 (1): 22-28
被引量:148
标识
DOI:10.1038/s41566-017-0054-7
摘要
Graphene, a unique two-dimensional material of carbon in a honeycomb lattice, has brought remarkable breakthroughs across the domains of electronics, mechanics, and thermal transport, driven by the quasiparticle Dirac fermions obeying a linear dispersion. Here we demonstrate a counter-pumped all-optical difference frequency process to coherently generate and control THz plasmons in atomic layer graphene with an octave tunability and high efficiency. We leverage the inherent surface asymmetry of graphene for a strong second-order nonlinear polarizability chi(2), which together with tight plasmon field confinement, enables a robust difference frequency signal at THz frequencies. The counter-pumped resonant process on graphene uniquely achieves both energy and momentum conservation. Consequently we demonstrate a dual-layer graphene heterostructure that achieves the charge- and gate-tunability of the THz plasmons over an octave, from 9.4 THz to 4.7 THz, bounded only by the pump amplifier optical bandwidth. Theoretical modeling supports our single-volt-level gate tuning and optical-bandwidth-bounded 4.7 THz phase-matching measurements, through the random phase approximation with phonon coupling, saturable absorption, and below the Landau damping, to predict and understand the graphene carrier plasmon physics.
科研通智能强力驱动
Strongly Powered by AbleSci AI