Resonant enhancement of terahertz dynamics in double-barrier resonant tunnelling diodes

Abstract

Terahertz dynamics in double-barrier resonant-tunnelling devices are studied using a Langevin equation approach taking into account the dynamic motion of electrons in the contacts. Damping constants are determined by the second-order perturbation for the Coulomb interaction between electrons inside each contact. It turns out that the present theory, which does not include empirical parameters, predicts resonance enhancements in the frequency response function and the noise spectrum of the tunnelling current in the terahertz region. It is shown that the 3 dB bandwidth is dependent on temperature T and barrier width d and can be as high as several tens of THz in the devices with higher T and smaller d values because of the existence of the resonance enhancements.