High-energy electron emission from metallic nano-tips driven by intense single-cycle terahertz pulses.
High-energy electron emission from metallic nano-tips driven by intense single-cycle terahertz pulses.
复制标题
来自金属纳米尖的高能电子发射，由激烈的单周terahertz脉冲驱动。
DOI：
10.1038/ncomms13405
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发表时间：
2016-11-10
影响因子：
16.6
通讯作者：
Jones RR
中科院分区：
文献类型：
--
作者：
Li S;Jones RR
电子从原子中射出，随后在强激光场中被驱动到高能量，使得从阿秒脉冲产生到再散射电子成像的技术成为可能。类似的过程控制着纳米结构的强场电子发射，其中长波长辐射和大的局部场增强有望产生具有更高能量的电子，从而实现更高分辨率的时间分辨成像。在这里，我们报告使用单周期太赫兹脉冲驱动电子发射无偏纳米尖端。观察到超过5 keV的能量，大大大于以前在更高的驱动频率下获得的能量。尽管各自的局部场的大小有很大的差异，我们发现，最大电子能量仅微弱地依赖于尖端半径，10 nm<R<1,000 nm。由于场的单周期性质，预计高能电子发射仅限于单个爆发，可能使各种应用成为可能。 高能电子源是研究原子和亚原子尺度动力学的有力工具。在这里，李和琼斯展示了太赫兹驱动的电子发射，能量超过5千电子伏的纳米尖端，并研究其对尖端半径的依赖性。
Electrons ejected from atoms and subsequently driven to high energies in strong laser fields enable techniques from attosecond pulse generation to imaging with rescattered electrons. Analogous processes govern strong-field electron emission from nanostructures, where long wavelength radiation and large local field enhancements hold the promise for producing electrons with substantially higher energies, allowing for higher resolution time-resolved imaging. Here we report on the use of single-cycle terahertz pulses to drive electron emission from unbiased nano-tips. Energies exceeding 5 keV are observed, substantially greater than previously attained at higher drive frequencies. Despite large differences in the magnitude of the respective local fields, we find that the maximum electron energies are only weakly dependent on the tip radius, for 10 nm<R<1,000 nm. Due to the single-cycle nature of the field, the high-energy electron emission is predicted to be confined to a single burst, potentially enabling a variety of applications. High-energy electron sources are powerful tools for investigating dynamics at atomic and subatomic scales. Here, Li and Jones demonstrate the terahertz-driven emission of electrons with energies exceeding five kiloelectronvolts from nano-tips and study its dependence on the tip radius.