Chen Siyu, Shi Wenlu, Ho W
Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, United States.
Department of Chemistry, University of California, Irvine, California 92697-2025, United States.
Nano Lett. 2023 Apr 12;23(7):2915-2920. doi: 10.1021/acs.nanolett.3c00271. Epub 2023 Mar 31.
We report rectification spectroscopy (RS) for single molecules performed with continuous-wave terahertz (CW THz) radiation at the tunneling junction of a scanning tunneling microscope (STM) at 8 K. CW THz-RS serves as a new technique in single-molecule vibrational and magnetic excitation spectroscopy besides inelastic electron tunneling spectroscopy (IETS). By quantitatively studying IETS and THz RS, we show that CW THz induces a sinusoidal bias modulation with amplitude linearly dependent on the THz far-field amplitude. Such THz-induced bias modulation amplitude appears to be sensitive to the THz beam alignment but insensitive to variation in the tunneling gap far smaller than the THz wavelength.
我们报道了在8K温度下，利用扫描隧道显微镜（STM）隧道结处的连续波太赫兹（CW THz）辐射对单分子进行的整流光谱（RS）。除了非弹性电子隧穿光谱（IETS）之外，连续波太赫兹整流光谱（CW THz-RS）是单分子振动和磁激发光谱中的一项新技术。通过对IETS和太赫兹RS进行定量研究，我们表明连续波太赫兹会诱导出正弦偏置调制，其幅度与太赫兹远场幅度呈线性相关。这种太赫兹诱导的偏置调制幅度似乎对太赫兹光束对准敏感，但对远小于太赫兹波长的隧穿间隙变化不敏感。
