Differential tunnel transparency of a rectangular heterostructural barrier for the terahertz frequency range

Abstract

Phenomenological theory of tunnel emitter transit time oscillators for the terahertz range Ballistic and quasiballistic tunnel transit time oscillators for the terahertz range: Linear admittance Electron wave tunneling through a rectangular heterostructural emitter barrier is considered in the case of a homogeneous high-frequency ͑hf͒ alternating electric field directed normal to the barrier interfaces. This hf field leads not only to the well-known increase in a stationary tunnel current through the emitter barrier, which is proportional to E B 2 ͑where E B is the electric-field amplitude͒ but also to a linear ͑ϳE B ͒ increase in an alternating current ͑ac͒ through this barrier with the same frequency as the electric-field frequency. The ac is a sharp function of , which grows significantly with an increase in ͑typically in the terahertz range͒. In a certain intermediate current and frequency region, the above-mentioned increase in the ac is the dominating effect of the alternating field. Such an effect can be used to optimize tunnel barrier emitters for ballistic transit-time terahertz-range oscillators.