Formation of probability density waves and probability current density waves by excitation and decay of a doublet of quasistationary states of a three-barrier heterostructure upon scattering of gaussian wave packets

TL;DR

This paper investigates how scattering of Gaussian wave packets by a three-barrier heterostructure creates probability density and current density waves, revealing their dependence on the structure and initial wave packet, with implications for wave amplification.

Contribution

It provides a numerical-analytical simulation showing the formation of damped probability waves and their characteristics resulting from scattering on a doublet of quasi-stationary states.

Findings

Waves have frequency equal to the doublet energy difference.

Wave characteristics depend on initial packet and scattering amplitudes.

Repetition or amplification of electron wave emission is possible with periodic pumping.

Abstract

A numerical-analytical simulation of scattering by a three-barrier heterostructure of an electronic Gaussian wave packet, the spectral width of which is on the order of the distance between the levels of the doublet of quasi-stationary states, is carried out. It is shown that as a result of scattering, damped waves of electron charge and current densities are formed outside the double well, their characteristics are determined by the structure of the initial wave packet and the poles of the scattering amplitudes. The frequency of these waves is equal to the difference frequency of the doublet, the wavenumber is the difference between the wave numbers of free motion of electrons with resonant energies, and the speed of their propagation is the ratio of these quantities. The system can go into the regime of repetition or amplification of the emission of electron waves if a periodic resonant pumping of the doublet population is provided by scattering of a series of coherent wave packets.