Terahertz radiation-induced sub-cycle field electron emission across a split-gap dipole antenna

ORAL

Abstract

We use intense terahertz pulses to excite the resonant mode (0.6THz) of a micro-fabricated dipole antenna with a vacuum gap. The dipole antenna structure enhances the peak amplitude of the in-gap THz electric field by a factor of \textasciitilde 170. Above an in-gap E-field threshold amplitude of \textasciitilde 10 MVcm-1, THz-induced field electron emission is observed (TIFEE) as indicated by the field-induced electric current across the dipole antenna gap. Field emission occurs within a fraction of the driving THz period. Our analysis of the current (I) and incident electric field (E) is in agreement with a Millikan-Lauritsen analysis where log (I) exhibits a linear dependence on 1/E. Numerical estimates indicate that the electrons are accelerated to a value of approximately one tenth of the speed of light. (arXiv: 1508.04737)

*We acknowledge support from DOE-BES No. DE-FG02-09ER46643 and NSF No. ECCS-1309835

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Authors

  • Jingdi Zhang

    • Univ of California - San Diego
    • Department of Physics, University of California, San Diego
    • University of California San Diego

  • Xiaoguang Zhao

    • Department of Mechanical Engineering, Boston University

  • Kebin Fan

    • Department of Mechanical Engineering, Boston University

  • Xiaoning Wang

    • Department of Mechanical Engineering, Boston University

  • Gu-Feng Zhang

    • Department of Physics, University of California, San Diego

  • Kun Geng

    • Department of Physics, Boston University

  • Xin Zhang

    • Department of Mechanical Engineering, Boston University

  • Richard D. Averitt

    • Department of Physics, University of California, San Diego