论文标题
单分子分辨率超快速近野光学显微镜通过等离子体寿命延伸
Single-molecule-resolution ultrafast near-field optical microscopy via plasmon lifetime extension
论文作者
论文摘要
最近的一项研究表明：当长寿命颗粒位于等离子金属纳米颗粒附近时，等离激元振荡的寿命会延伸，但是，“仅”在该长生命粒子附近[PRB 101，035416（2020）]。在这里，我们表明这种现象可用于超高（单分子）分辨率超快无孔（散射）SNOM应用。我们使用3D Maxwell方程的确切解决方案。我们照亮了带有飞秒激光器的尖端顶端上的量子发射器（QE）的金属涂层硅尖端。除非在亚NM大小的量化宽松的附近，尖端中的近场诱导近场衰减迅速。因此，分辨率完全受量化宽度量的限制。由于在尖端顶点上定位量化宽松是具有挑战性的，因此我们提出了新发现的现象的使用。 2D材料中应力诱导的缺陷形成。当单层（例如，将过渡金属二北元化（TMD）转移到AFM尖端）时，2D TMD的尖端凹痕源于位于尖端最尖端点的缺陷中心。那正是它的顶点。此外，缺陷的共振可以通过施加到尖端的电压来调节。我们的方法同样可以用于无背景的非线性非线性成像，并促进单分子大小的化学操作。
A recent study shows that: when a long lifetime particle is positioned near a plasmonic metal nanoparticle, lifetime of plasmon oscillations extends, but, "only" near that long-life particle [PRB 101, 035416 (2020)]. Here, we show that this phenomenon can be utilized for ultrahigh (single-molecule) resolution ultrafast apertureless (scattering) SNOM applications. We use the exact solutions of 3D Maxwell equations. We illuminate a metal-coated silicon tip, a quantum emitter (QE) placed on the tip apex, with a femtosecond laser. The induced near-field in the apex decays rapidly except in the vicinity of the sub-nm-sized QE. Thus, the resolution becomes solely limited by the size of the QE. As positioning of a QE on the tip apex is challenging, we propose the use of a newly-discovered phenomenon; stress-induced defect formation in 2D materials. When a monolayer, e.g., transition metal dichalcogenide (TMD) is transferred to the AFM tip, the tip indentation of 2D TMD originates a defect-center located right at the sharpest point of the tip; that is exactly at its apex. Moreover, the resonance of the defect is tunable via a voltage applied to the tip. Our method can equally be used for background-noise-free nonlinear imaging and for facilitating single-molecule-size chemical manipulation.
