Interatomic Coulombic decay in two coupled quantum wells

Abstract

Interatomic coulombic decay (ICD) is a relaxation process induced by electronic correlation. In this work we study the ICD process in a two coupled Quantum wells (QWs) nano-structure. We study a simple one-dimensional effective potential using experimental parameters of the semiconductor QW layers i.e. using the single band effective-mass approximation . In our calculations we consider the discontinuity of the effective mass of the electron in each of the QW layers. We control the ICD lifetime by changing the distance between the two wells. The expected overall trend is a decrease of ICD lifetime with a decrease in the distance between the wells. We show that the distance can be tuned such that the emitted ICD electron is trapped in a meta-stable state in the continuum i.e. a one electron resonance state. This causes the life time of the ICD to be an order of magnitude smaller even in very long distances, and improves the efficiency of the ICD. For the ICD to be dominant decay mechanism it must prevail over all other possible competitive decay processes. We have found that the lifetime of the ICD is on the timescale of picoseconds. Therefore, based on our results we can design an experiment that will observe the ICD phenomenon in QWs nano-structure for the first time. This work can lead to designing a wavelength sensitive detector which is efficient even in low intensities.

Strong field control of the interatomic Coulombic decay process in quantum dots

“…Ideas of its device application advanced to pairs of quantum wells [26] and quantum dots [24,25] that offer a number of control options for ICD. Among these are differently-shaped, focused, and polarized initiating laser pulses [51].…”

“…as next-generation infrared photo detector or solar cell. This is because the QD pair's electronic structure, and hence the ICD performance, can be custom made through geometry control of the QDs' distance [25,38] (this holds likewise for quantum wells [26]), widths [43], and heights [43,44].…”

“…[1] -this slogan summarizes the nearly twenty years of success history of the ultrafast interatomic (intermolecular) Coulombic decay (ICD) process from its first theoretical prediction by Cederbaum, Zobeley, and Tarantelli [2] to its widespread theoretical and experimental observation [3,4] in various atomic and molecular systems including clusters of noble gas atoms [5,6,7,8], endohedral fullerenes [9,10,11], aqueous solutions [12,13,14,15,16,17], biological systems [18,19,20,21,22,23], and nanomaterials [24,25,26] just to name a few.…”

Interatomic and Intermolecular Coulombic Decay

“…Intraband relaxation of the electron in one well then leads to the emission of the electron from the second well into the surrounding substrate. 478 Although, unlike in QDs, the electrons in QWs are free to move in two dimensions, electronic excitation followed by ICD is still possible provided that in preparing the decaying state the bottom of each respective conduction subband is populated. Moreover, under an additional condition of large separation between the wells, it was shown that the electron emission in ICD occurs mostly in the direction of layer growth.…”

Acoustic phonon impact on the inter-Coulombic decay process in charged quantum dot pairs

“…It is nowadays widely known in atomic and molecular cluster physics [71,72], but basically understood to potentially appear in many more fields as e.g. biophysics [73][74][75][76] or nanoscience [77][78][79]. In any case an excited electron in one of the subsystems (atom, molecule, molecular fragment, nanoparticle, QD, etc.…”