Influence of Coulomb Blockade on Wave Packet Dynamics in Nanoscale Structures

Abstract

Influence of Coulomb blockade on electron scattering by a quantum dot has been theoretically investigated using a multielectron wave packet simulation technique based on the time-dependent Hartree–Fock approximation. In our simulation, the bound states of electrons in the dot are self-consistently determined. We confirmed that Koopman's theorem keeps its validity only for weak Coulomb interactions. Moreover, we show that the maximum number of electrons trapped in the dot does depend on the strength of Coulomb interactions. Consequently, the transmission and reflection probabilities of an incident wave packet toward the dot are strongly influenced by the number of trapped electrons in the dot.

Effect of long-range Coulomb interactions on electron transport in a nanoscale one-dimensional ring

“…1 is the one-body term. 18,22,23,32) The time-dependent Hartree-Fock equation is equivalent to the random phase approximation (RPA) in the short period time limit. 33) Thus, we are able to include the many-body correlation effect of the electrons in the range of the RPA in our calculations.…”

“…In our previous work, 22,23) we showed that the nature of the electron transport varies drastically depending on the strength of the long-range Coulomb interactions. Generally speaking, electrons make Bloch wave states in the weak Coulomb interaction limit whereas they make localized states in the strong interaction limit.…”

Interacting Electron Wave Packet Dynamics in a Two-Dimensional Nanochannel

“…Wave packet approaches have been considered previously, but relied on strictly one-dimensional structures and/or on noninteracting electrons, or were based on approximate schemes such as the time-dependent Hartree-Fock theory. [11][12][13][14][15][16][17] Below, we study in detail the effect of Coulomb repulsion and an external electric field on wave packet propagation in a two-dimensional nanochannel. A main finding is that Coulomb repulsion redistributes the charge density to the channel walls, which makes electron transport more sensitive to perturbations at the interface.…”

“…The stabilizing effect of an electric field has also been observed for strictly one-dimensional interacting wave packets based on a time-dependent Hartree-Fock approach, which additionally revealed a bunching phenomenon of wave packets within the one-dimensional channel. [11] In conclusion, we have considered the effect of Coulomb repulsion and external field on the electron dynamics in a nanochannel, by exactly solving the Schroedinger equation for a pair of interacting and propagating electrons. This is in contrast to previous wave packet studies that mostly focused on single electrons and/or one-dimensional nanostructures.…”