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.

中文翻译：

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利用载波包络相位控制的太赫兹电场调整隧道结中的单周期近场

可以通过利用时空可调谐的近场来操纵在远超过光的衍射极限的条件下发生的光场驱动过程。在纳米间隙电极之间形成的隧道结中，量身定制的载流子包络相可以精确控制这些过程。尤其是，隧道结中近场的表征和主动控制对于在原子尺度上推进对光场驱动过程的精细操作至关重要。在这里，我们证明可以通过具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。对相分辨子周期电子隧穿动力学的测量表明，远场和近场单周期THz波形之间出乎意料的大载流子包络相移。相移源自尖端样本配置的波长尺度特征。通过使用双相双脉冲方案，在飞秒时间范围内相干地操纵了电子隧穿。我们的新处方-在隧道结中的场附近对单周期太赫兹进行原位定制-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。