Diamagnetic susceptibility of an off-center hydrogenic donor in pyramid-like and cone-like quantum dots

Avazzadeh, Z.; Bahramiyan, H.; Khordad, R.; Mohammadi, Seyyed Abbas

doi:10.1140/epjp/i2016-16121-8

Cited by 21 publications

(13 citation statements)

References 26 publications

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“…The achievements of modern semiconductor technologies provide ample opportunities for the design and production of the semiconductor QDs having nontrivial geometric shapes [1][2][3][4][5][6][7][8]. The energy spectrum of the QD is linear due to the complete quantization of charge carriers' (CCs) motion, which makes it possible to call these structures artificial atoms.…”

Section: Introductionmentioning

confidence: 99%

Spontaneous Exciton Collapse in a Strongly Flattened Ellipsoidal InSb Quantum Dot

Dvoyan

Karoui²,

Vlahović³

2022

Nanoscale Res Lett

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Electronic and excitonic states in an InSb strongly flattened ellipsoidal quantum dot (QD) with complicated dispersion law are theoretically investigated within the framework of the geometric adiabatic approximation in the strong, intermediate, and weak quantum confinement regimes. For the lower levels of the spectrum, the square root dependence of energy on QD sizes is revealed in the case of Kane’s dispersion law. The obtained results are compared to the case of a parabolic (standard) dispersion law of charge carriers. The possibility of the accidental exciton instability is revealed for the intermediate quantum confinement regime. For the weak quantum confinement regime, the motion of the exciton's center-of-gravity is quantized, which leads to the appearance of additional Coulomb-like sub-levels. It is revealed that in the case of the Kane dispersion law, the Coulomb levels shift into the depth of the forbidden band gap, moving away from the quantum confined level, whereas in the case of the parabolic dispersion law, the opposite picture is observed. The corresponding selection rules of quantum transitions for the interband absorption of light are obtained. New selection rules of quantum transitions between levels conditioned by 2D exciton center of mass vertical motion quantization in a QD are revealed. The absorption threshold behavior characteristics depending on the QDs geometrical sizes are also revealed.

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Section: Introductionmentioning

confidence: 99%

Spontaneous Exciton Collapse in a Strongly Flattened Ellipsoidal InSb Quantum Dot

Dvoyan

Karoui²,

Vlahović³

2022

Nanoscale Res Lett

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“…Entre las técnicas para la fabricación de puntos cuánticos se encuentran la epitaxia de haces moleculares y la bien conocida Stranski-Krastanov, mediante la cuales es posible obtener puntos cuánticos de diferentes formas tales como pirámides y lentes, entre otras Lelong y Bastard (1996) ;Iqraoun, et al (2017). Además de las diferentes formas geométricas, se ha encontrado que los campos eléctricos y magnéticos, la radiación láser intensa no resonante, la presión hidrostática, y la temperatura modifican las propiedades electrónicas y ópticas de tales sistemas de dimensión cero Hiruma, et al (2006); Avazzadeh, et al (2016); Iqraoun, et al (2017). Una gran variedad de estudios se ha dedicado también a los efectos de la presencia de impurezas Hiruma, et al (2006); Ngo, et al (2006).…”

Section: Introductionunclassified

“…Para el caso particular de un punto cuántico en forma de cono se han realizado muchos estudios, entre ellos: i) la generación de segundo y tercer armónico, ii) efectos de la posición de impureza sobre los niveles de energía, iii) el cálculo de la susceptibilidad diamagnética de una impureza donadora hidrogenoide descentrad y iv) los efectos simultáneos de un campo eléctrico externo y la posición de impurezas sobre la rectificación óptica no lineal Gil, et al (2017);Hiruma, et al (2006); Lelong y Bastard (1996); Avazzadeh, et al (2016);Yiming, et al (2001). Igualmente, se ha investigado teóricamente la absorción óptica relacionada con impurezas donadoras, los cambios relativos del índice de refracción y la dispersión Raman.…”

Section: Introductionunclassified

Efectos geométricos sobre las propiedades electrónicas y ópticas de puntos cuánticos cónicos de GaN (Punto cuántico cónico)

Caicedo

Henao

Vinasco

et al. 2020

reveia

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Haciendo uso de la aproximación de masa efectiva y de cálculos numéricos con el método de elementos finitos, se reportan las propiedades ópticas y electrónicas de un electrón confinado en un punto cuántico de GaN, en forma de sector cónico esférico. Se reportan los estados electrónicos, el cuadrado del momento de dipolo y los coeficientes de absorción óptica y de cambios en el índice de refracción como funciones del radio y del ángulo apical de la estructura. Del estudio se puede concluir que: i) elecciones adecuadas del ángulo apical y del radio del punto cuántico pueden dar origen a magnificaciones en las propiedades ópticas y ii) corrimientos al rojo de las estructuras resonantes de las propiedades ópticas se asocian claramente con el aumento tanto del ángulo apical como del radio de la estructura.

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“…Using variational method, Anitha and Arulmozhi [38] investigated the influence of spatially dependent effective mass, conduction band non-parabolicity and dielectric screening function on exciton binding energy in a pyramid-shaped QD. Based on the finite-element method and the Arnoldi algorithm, Avazzadeh et al [39] studied the diamagnetic susceptibility of an off-center hydrogenic donor impurity confined in pyramid and cone-like quantum dots. Effect of impurity position on the electronic structure, hydrogenic impurity binding energy and third harmonic generation of a pyramid and a cone like quantum dot was investigated by Khordad and Bahramian [40].…”

Section: Introductionmentioning

confidence: 99%

Finite difference time domain simulation of arbitrary shapes quantum dots

et al. 2019

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Utilizing the finite difference time domain (FDTD) method, energy eigenvalues of spherical, cylindrical, pyramidal and cone-like quantum dots are calculated. To do this, by the imaginary time transformation, we transform the schrödinger equation into a diffusion equation. Then, the FDTD algorithm is hired to solve this equation. We calculate four lowest energy eigenvalues of these QDs and then compared the simulation results with analytical ones. Our results clearly show that simulation results are in very good agreement with analytical results. Therefore, we can use the FDTD method to find accurate results for the Schrödinger equation.

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Diamagnetic susceptibility of an off-center hydrogenic donor in pyramid-like and cone-like quantum dots

Cited by 21 publications

References 26 publications

Spontaneous Exciton Collapse in a Strongly Flattened Ellipsoidal InSb Quantum Dot

Spontaneous Exciton Collapse in a Strongly Flattened Ellipsoidal InSb Quantum Dot

Efectos geométricos sobre las propiedades electrónicas y ópticas de puntos cuánticos cónicos de GaN (Punto cuántico cónico)

Finite difference time domain simulation of arbitrary shapes quantum dots

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