Sub-femtosecond electron transport in a nanoscale gap
Sub-femtosecond electron transport in a nanoscale gap
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DOI：
10.1038/s41567-019-0745-8
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发表时间：
2019-12-23
期刊：
影响因子：
19.6
通讯作者：
Brida, Daniele
中科院分区：
文献类型：
--
作者：
Ludwig, Markus;Aguirregabiria, Garikoitz;Brida, Daniele
电子穿过等离子体蝴蝶结天线差距的单周期干涉自相关测量和定量模型提供了对驱动电子转移的物理相互作用的深入了解。与几个周期脉冲相关的强场可以驱动高度非线性现象，允许直接控制凝聚态系统中的电子。在这种情况下，通过采用近红外单周期脉冲对，我们测量的超快电流的光场发射在一个单一的等离子体纳米电路的纳米间隙引起的干涉自相关。这种超快电子纳米传输的动力学取决于光驱动脉冲的精确时间场轮廓。电流自相关获得亚飞秒时间分辨率作为脉冲延迟和绝对载波包络相位的函数。实验的定量建模使我们能够监测系统中诱导的电子密度和电流的时空演化，并阐明等离子体间隙中强光场驱动的电子转移的物理基础。具体来说，我们澄清的载波包络相位的驱动脉冲，等离子体共振和微扰运动之间的相互作用。
Single-cycle interferometric autocorrelation measurements of electrons tunnelling across the gap of a plasmonic bowtie antenna and quantitative models provide insight into the physical interactions that drive the electron transfer.The strong fields associated with few-cycle pulses can drive highly nonlinear phenomena, allowing the direct control of electrons in condensed matter systems. In this context, by employing near-infrared single-cycle pulse pairs, we measure interferometric autocorrelations of the ultrafast currents induced by optical field emission at the nanogap of a single plasmonic nanocircuit. The dynamics of this ultrafast electron nanotransport depends on the precise temporal field profile of the optical driving pulse. Current autocorrelations are acquired with sub-femtosecond temporal resolution as a function of both pulse delay and absolute carrier-envelope phase. Quantitative modelling of the experiments enables us to monitor the spatiotemporal evolution of the electron density and currents induced in the system and to elucidate the physics underlying the electron transfer driven by strong optical fields in plasmonic gaps. Specifically, we clarify the interplay between the carrier-envelope phase of the driving pulse, plasmonic resonance and quiver motion.