Seven Études on dynamical Keldysh model

We present a comprehensive pedagogical discussion of a family of models describing the propagation of a single particle in a multicomponent non-Markovian Gaussian random field. We report some exact results for single-particle Green's functions, self-energy, vertex part and T-matrix. These resu...

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Main Author: Dmitri V. Efremov, Mikhail N. Kiselev
Format: Article
Language:English
Published: SciPost 2022-12-01
Series:SciPost Physics Lecture Notes
Online Access:https://scipost.org/SciPostPhysLectNotes.65
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author Dmitri V. Efremov, Mikhail N. Kiselev
author_facet Dmitri V. Efremov, Mikhail N. Kiselev
author_sort Dmitri V. Efremov, Mikhail N. Kiselev
collection DOAJ
description We present a comprehensive pedagogical discussion of a family of models describing the propagation of a single particle in a multicomponent non-Markovian Gaussian random field. We report some exact results for single-particle Green's functions, self-energy, vertex part and T-matrix. These results are based on a closed form solution of the Dyson equation combined with the Ward identity. Analytical properties of the solution are discussed. Further we describe the combinatorics of the Feynman diagrams for the Green's function and the skeleton diagrams for the self-energy and vertex, using recurrence relations between the Taylor expansion coefficients of the self-energy. Asymptotically exact equations for the number of skeleton diagrams in the limit of large $N$ are derived. Finally, we consider possible realizations of a multicomponent Gaussian random potential in quantum transport via complex quantum dot experiments.
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spelling doaj.art-214de8051e724827ae988c6bac65cedf2022-12-22T04:40:01ZengSciPostSciPost Physics Lecture Notes2590-19902022-12-016510.21468/SciPostPhysLectNotes.65Seven Études on dynamical Keldysh modelDmitri V. Efremov, Mikhail N. KiselevWe present a comprehensive pedagogical discussion of a family of models describing the propagation of a single particle in a multicomponent non-Markovian Gaussian random field. We report some exact results for single-particle Green's functions, self-energy, vertex part and T-matrix. These results are based on a closed form solution of the Dyson equation combined with the Ward identity. Analytical properties of the solution are discussed. Further we describe the combinatorics of the Feynman diagrams for the Green's function and the skeleton diagrams for the self-energy and vertex, using recurrence relations between the Taylor expansion coefficients of the self-energy. Asymptotically exact equations for the number of skeleton diagrams in the limit of large $N$ are derived. Finally, we consider possible realizations of a multicomponent Gaussian random potential in quantum transport via complex quantum dot experiments.https://scipost.org/SciPostPhysLectNotes.65
spellingShingle Dmitri V. Efremov, Mikhail N. Kiselev
Seven Études on dynamical Keldysh model
SciPost Physics Lecture Notes
title Seven Études on dynamical Keldysh model
title_full Seven Études on dynamical Keldysh model
title_fullStr Seven Études on dynamical Keldysh model
title_full_unstemmed Seven Études on dynamical Keldysh model
title_short Seven Études on dynamical Keldysh model
title_sort seven etudes on dynamical keldysh model
url https://scipost.org/SciPostPhysLectNotes.65
work_keys_str_mv AT dmitrivefremovmikhailnkiselev sevenetudesondynamicalkeldyshmodel