Pulse Propagation in Resonant Tunneling

TL;DR

This paper analyzes how Gaussian pulses propagate through resonant tunneling structures, revealing two regimes based on resonance width and identifying effects like pulse deformation, delay, and interference oscillations.

Contribution

It provides an analytical solution for pulse tunneling through resonances, distinguishing between broad and narrow resonance regimes and describing associated pulse behaviors.

Findings

Broad resonances produce weakly deformed, slightly delayed pulses.

Narrow resonances cause exponential decay and interference oscillations.

Slow decay limits pulse transfer rate.

Abstract

We consider the analytically solvable model of a Gaussian pulse tunneling through a transmission resonance with a Breit-Wigner characteristic. The solution allows for the identification of two opposite pulse propagation regimes: if the resonance is broad compared to the energetic width of the incident Gaussian pulse a weakly deformed and slightly delayed transmitted Gaussian pulse is found. In the opposite limit of a narrow resonance the dying out of the transmitted pulse is dominated by the slow exponential decay characteristic of a quasi-bound state with a long life time (decaying state). We discuss the limitation of the achievable pulse transfer rate resulting from the slow decay. Finally, it is demonstrated that for narrow resonances a small second component is superimposed to the exponential decay which leads to characteristic interference oscillations.