ANALYTICAL MODEL OF HIGH-FREQUENCY RESONANT TUNNELING - THE 1ST-ORDER AC CURRENT RESPONSE

A high-frequency analytical model for double-barrier resonant tunneling is formulated. In evaluating the device frequency response, a dc voltage is applied to bias the double barrier into the resonant-tunneling regime, and a small-amplitude ac modulation is then added. The ac modulation causes transmission sidebands, in addition to the direct transmission peak when an electron traverses the double barrier. Analytical expressions for the first-order sidebands are derived. Using a Breit-Wigner expansion of the sidebands in the neighborhood of a resonance, the small-signal ac current response is evaluated in closed form. The device frequency characteristic is discussed, and a quantum inductance is confirmed, which arises from the resonance lifetime. An analytical model is useful in understanding the device physics and in applications.