Influence of impurity propagation and concomitant enhancement of impurity spread on excitation profile of doped quantum dots

Abstract

We investigate the excitation behavior of a repulsive impurity doped quantum dot under the combined influence of dopant drift and associated time variation in its spatial spread. We have considered Gaussian impurity centers. In order to make the investigation rational, the time-dependence of the spatial spread has been connected with the instantaneous location of the dopant. Looking at the general applicability of the findings, we have considered linear and random propagation of the dopant. For a systematic analysis, we have proceeded in a stepwise manner during the investigation. Thus, at first we have not considered the time-dependence of spatial spread of dopant and concentrated only on the dopant drift. Subsequently, we have introduced time-dependence in the spatial spread and observed the outcome. Although the incorporation of time-dependence in spatial stretch makes the calculation much more tedious and involved, yet this adequately describes the role played by the time-varying impurity domain exclusively in modulating the excitation rate. The varied nature of dopant propagation interplays delicately with the time-dependent modulation of its spatial stretch giving some important insight into the physics underlying the excitation process.

Coupled influence of damped propagation of dopant and external oscillatory field on excitation kinetics of doped quantum dot

“…The time‐independent Schrödinger equation has been solved using variational method expressing the trial wave function as a superposition of the product of harmonic oscillator eigenfunctions . In the linear variational calculation, an appreciably large number of basis functions have been exploited after making the required convergence test.…”

“…The said study has produced sufficient interest as most low‐dimensional structures contain doped regions (). Later on we have upgraded our previous theoretical framework () by incorporating time‐dependent alteration in the spatial stretch of the dopant associated with its drift (). In connection with the dynamical aspects mentioned above there are also some important works which study the effect of applied electric field on doped quantum wells and dots .…”

“…The parameter inside the exponential takes care of the influence of damping. Following our earlier improved model () we have also considered the appropriate time‐dependent modulation of spatial stretch of impurity () accompanying the damped movement of the dopant. We have determined the time‐average excitation rate () as a functions of characteristic field parameters, namely, the oscillation frequency () and the intensity () under low, intermediate, and highly damped conditions.…”

Influence of Oscillatory Impurity Potential and Concurrent Gasping of Impurity Spread on Excitation Profile of Doped Quantum Dots

“…The matrix element involving any two arbitrary eigenstates and of 0 due to 1 ( ) reads (Details of derivation and various relevant quantities are given in references [29,30]…”

“…We conceive such a gasping impurity with a view to making the problem more realistic and rational. Recently we have done some works on this kind of time-dependent impurity spread in a different contexts [29,30]. Thus, in the present enquiry we explore the combined role of oscillatory impurity potential and impurity stretch on the said excitation profile.…”