Spectral function of InAs∕InGaAs quantum dots in a well detector using Green’s function

2006 ◽  
Vol 100 (9) ◽  
pp. 093102 ◽  
Author(s):  
M. A. Naser ◽  
M. J. Deen ◽  
D. A. Thompson
Keyword(s):  
Quantum Dots ◽  
Green’S Function ◽  
Spectral Function ◽  
Green's Function ◽  
Well Detector

Nonequilibrium-Green’s-function theory of transport in interacting quantum dots

1994 ◽  
Vol 50 (7) ◽  
pp. 4482-4496 ◽  
Author(s):  
Lindor E. Henrickson ◽  
Arnold J. Glick ◽  
Garnett W. Bryant ◽  
David F. Barbe
Keyword(s):  
Quantum Dots ◽  
Green’S Function ◽  
Green's Function ◽  
Function Theory ◽  
Nonequilibrium Green's Function ◽  
Nonequilibrium Green’S Function

Elastic Fields of Quantum Dots in Multilayered Semiconductors: A Novel Green’s Function Approach

2003 ◽  
Vol 70 (2) ◽  
pp. 161-168 ◽  
Author(s):  
B. Yang ◽  
E. Pan
Keyword(s):  
Quantum Dots ◽  
Green’S Function ◽  
Green's Function ◽  
Green's Functions ◽  
Green’S Functions ◽  
Point Sources ◽  
Reciprocal Theorem ◽  
Wetting Layer ◽  
Volume Integral ◽  
Elastic Fields

We present an efficient and accurate continuum-mechanics approach to predict the elastic fields in multilayered semiconductors due to buried quantum dots (QDs). Our approach is based on a novel Green’s function solution in anisotropic and linearly elastic multilayers, derived within the framework of generalized Stroh formalism and Fourier transforms, in conjunction with the Betti’s reciprocal theorem. By using this approach, the induced elastic fields due to QDs with general misfit strains are expressed as a volume integral over the QDs domains. For QDs with uniform misfit strains, the volume integral involved is reduced to a surface integral over the QDs boundaries. Further, for QDs that can be modeled as point sources, the induced elastic fields are then derived as a sum of the point-force Green’s functions. In the last case, the solution of the QD-induced elastic field is analytical, involving no numerical integration, except for the evaluation of the Green’s functions. As numerical examples, we have studied a multilayered semiconductor system of QDs made of alternating GaAs-spacer and InAs-wetting layers on a GaAs substrate, plus a freshly deposited InAs-wetting layer on the top. The effects of vertical and horizontal arrays of QDs and of thickness of the top wetting layer on the QD-induced elastic fields are examined and some new features are observed that may be of interest to the designers of semiconductor QD superlattices.

scholarly journals Equation-of-Motion Coupled-Cluster Cumulant Green’s Function for Excited States and X-Ray Spectra

2021 ◽  
Vol 9 ◽  
Author(s):  
F. D. Vila ◽  
J. J. Kas ◽  
J. J. Rehr ◽  
K. Kowalski ◽  
B. Peng
Keyword(s):  
Green’S Function ◽  
Spectral Function ◽  
Excited States ◽  
Green's Function ◽  
Coupled Cluster ◽  
X Ray ◽  
Molecular Systems ◽  
Self Energy ◽  
The Core ◽  
Non Linear

Green’s function methods provide a robust, general framework within many-body theory for treating electron correlation in both excited states and x-ray spectra. Conventional methods using the Dyson equation or the cumulant expansion are typically based on the GW self-energy approximation. In order to extend this approximation in molecular systems, a non-perturbative real-time coupled-cluster cumulant Green’s function approach has been introduced, where the cumulant is obtained as the solution to a system of coupled first order, non-linear differential equations. This approach naturally includes non-linear corrections to conventional cumulant Green’s function techniques where the cumulant is linear in the GW self-energy. The method yields the spectral function for the core Green’s function, which is directly related to the x-ray photoemission spectra (XPS) of molecular systems. The approach also yields very good results for binding energies and satellite excitations. The x-ray absorption spectrum (XAS) is then calculated using a convolution of the core spectral function and an effective, one-body XAS. Here this approach is extended to include the full coupled-cluster-singles (CCS) core Green’s function by including the complete form of the non-linear contributions to the cumulant as well as all single, double, and triple cluster excitations in the CC amplitude equations. This approach naturally builds in orthogonality and shake-up effects analogous to those in the Mahan-Noizeres-de Dominicis edge singularity corrections that enhance the XAS near the edge. The method is illustrated for the XPS and XAS of NH3.

Single Particle Green's Function in the Electron–Plasmon Approximation

1973 ◽  
Vol 51 (1) ◽  
pp. 102-110 ◽  
Author(s):  
B. Bergersen ◽  
F. W. Kus ◽  
C. Blomberg
Keyword(s):  
Green’S Function ◽  
Spectral Function ◽  
Density Of States ◽  
Green's Function ◽  
Single Particle ◽  
Perturbation Expansion ◽  
Electron Correlations ◽  
Crucial Feature ◽  
Direct Perturbation ◽  
The One

A discussion of how to carry out a direct perturbation expansion for the one-electron Green's function is given using an electron–plasmon model for the conduction electron correlations. A crucial feature of the method is the consistent extraction of energy shifts. Numerical results for the spectral function and the density of states are given in lowest order and the generalization to higher order is discussed. The present work differs from previous ones in that the method used cannot give rise to "plasmaron"-like excitations. Other singular features also come in differently.

Detection of extremely large magnetoresistance in a ring-shaped array of magnetic quantum dots with very high performance and controllable parameters

2022 ◽  
Author(s):  
Mohammad Molavi ◽  
Edris Faizabadi
Keyword(s):  
Quantum Dots ◽  
Green’S Function ◽  
Green's Function ◽  
High Performance ◽  
Function Technique ◽  
Mr Effect ◽  
Magnetic Quantum Dots ◽  
Very High

By means of Green’s function technique, we study the magnetoresistance (MR) effect in a ring-shaped array of magnetic quantum dots (QDs), with or without magnetic leads, while the magnetic QDs...

Green's Function Method for Calculation of Strain Field Due to a Quantum Dot in a Semi-Infinite Anisotropic Solid

2002 ◽  
Vol 727 ◽  
Author(s):  
V.K. Tewary
Keyword(s):  
Quantum Dots ◽  
Free Surface ◽  
Quantum Dot ◽  
Green’S Function ◽  
Green's Function ◽  
Strain Field ◽  
Function Method ◽  
Field Interaction ◽  
Green’S Function Method ◽  
Analytic Expressions

AbstractA computationally convenient Green's function method is described for calculation of strain characteristics of quantum dots in an anisotropic semi- infinite solid containing a free surface. Semi-analytic expressions are derived for the strain field due to a quantum dot, strain energy of a quantum dot, and strain- field interaction between 2 quantum dots. Numerical results are presented for the strain field due to a quantum dot in GaAs. It is shown that the effect of the free surface, which has been neglected in earlier calculations using Green's function methods, is quite significant.

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