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

Jingdi Zhang, Xiaoguang Zhao, Kebin Fan, Xiaoning Wang, Gu-Feng Zhang, Kun Geng, Xin Zhang, Richard D. Averitt

http://www.mathpubs.com/detail/1508.04737v1/Terahertz-radiation-induced-sub-cycle-field-electron-emission-across-a-split-gap-dipole-antenna

We use intense terahertz pulses to excite the resonant mode (0.6 THz) 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 ~170. Above an in-gap E-field threshold amplitude of ~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.