Tailoring Single-Cycle Near-Field in a Tunnel Junction with Carrier-Envelope Phase-Controlled Terahertz Electric Fields
Tailoring Single-Cycle Near-Field in a Tunnel Junction with Carrier-Envelope Phase-Controlled Terahertz Electric Fields
复制标题
利用载流子包络相控太赫兹电场在隧道结中定制单周期近场
DOI：
10.1021/acs.nanolett.8b02161
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发表时间：
2018
期刊：
影响因子：
10.8
通讯作者：
and J. Takeda
中科院分区：
文献类型：
--
作者：
K. Yoshioka;I. Katayama;Y. Arashida;A. Ban;Y. Kawada;H. Takahashi;and J. Takeda
在远远超出光衍射极限的条件下发生的光场驱动过程可以通过利用时空可调谐近场来操纵。纳米间隙电极之间形成的隧道结中的定制载流子包络相允许对这些过程进行精确控制。特别是，隧道结中近场的表征和主动控制对于推进原子尺度光场驱动过程的精细操纵至关重要。在这里，我们证明可以通过带有移相器的太赫兹扫描隧道显微镜（THz-STM）在隧道结中产生理想的相控近场。相位分辨子周期电子隧道动力学的测量揭示了远场和近场单周期太赫兹波形之间意想不到的大载流子包络相移。相移源于尖端-样品配置的波长尺度特征。通过使用双相双脉冲方案，可以在飞秒时间尺度上连贯地操纵电子隧道。我们的新方案——隧道结中单周期太赫兹近场的原位定制——将为超快原子级电子学和计量学提供前所未有的电子控制。
Light-field-driven processes occurring under conditions far beyond the diffraction limit of the light can be manipulated by harnessing spatiotemporally tunable near fields. A tailor-made carrier envelope phase in a tunnel junction formed between nanogap electrodes allows precisely controlled manipulation of these processes. In particular, the characterization and active control of near fields in a tunnel junction are essential for advancing elaborate manipulation of light-field-driven processes at the atomic-scale. Here, we demonstrate that desirable phase-controlled near fields can be produced in a tunnel junction via terahertz scanning tunneling microscopy (THz-STM) with a phase shifter. Measurements of the phase-resolved subcycle electron tunneling dynamics revealed an unexpected large carrier-envelope phase shift between far-field and near-field single-cycle THz waveforms. The phase shift stems from the wavelength-scale feature of the tip–sample configuration. By using a dual-phase double-pulse scheme, the electron tunneling was coherently manipulated over the femtosecond time scale. Our new prescription—in situ tailoring of single-cycle THz near fields in a tunnel junction—will offer unprecedented control of electrons for ultrafast atomic-scale electronics and metrology.