Electron-Electron Interactions in Device Simulation via Non-equilibrium Green's Functions and the GW Approximation

Fuente: arXiv
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Main Authors: Deuschle, Leonard, Cao, Jiang, Ziogas, Alexandros Nikolaos, Winka, Anders, Maeder, Alexander, Vetsch, Nicolas, Luisier, Mathieu
Format: Preprint
Published: 2024
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author Deuschle, Leonard
Cao, Jiang
Ziogas, Alexandros Nikolaos
Winka, Anders
Maeder, Alexander
Vetsch, Nicolas
Luisier, Mathieu
author_facet Deuschle, Leonard
Cao, Jiang
Ziogas, Alexandros Nikolaos
Winka, Anders
Maeder, Alexander
Vetsch, Nicolas
Luisier, Mathieu
contents The continuous scaling of metal-oxide-semiconductor field-effect transistors (MOSFETs) has led to device geometries where charged carriers are increasingly confined to ever smaller channel cross sections. This development is associated with reduced screening of long-range Coulomb interactions. To accurately predict the behavior of such ultra-scaled devices, electron-electron (e-e) interactions must be explicitly incorporated in their quantum transport simulation. In this paper, we present an \textit{ab initio} atomistic simulation framework based on density functional theory, the non-equilibrium Green's function formalism, and the self-consistent GW approximation to perform this task. The implemented method is first validated with a carbon nanotube test structure before being applied to calculate the transfer characteristics of a silicon nanowire MOSFET in a gate-all-around configuration. As a consequence of e-e scattering, the energy and spatial distribution of the carrier and current densities both significantly change, while the on-current of the transistor decreases owing to the Coulomb repulsion between the electrons. Furthermore, we demonstrate how the resulting bandgap modulation of the nanowire channel as a function of the gate-to-source voltage could potentially improve the device performance. To the best of our knowledge, this study is the first one reporting large-scale atomistic quantum transport simulations of nano-devices under non-equilibrium conditions and in the presence of e-e interactions within the GW approximation.
format Preprint
id arxiv_https___arxiv_org_abs_2412_12986
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Electron-Electron Interactions in Device Simulation via Non-equilibrium Green's Functions and the GW Approximation
Deuschle, Leonard
Cao, Jiang
Ziogas, Alexandros Nikolaos
Winka, Anders
Maeder, Alexander
Vetsch, Nicolas
Luisier, Mathieu
Mesoscale and Nanoscale Physics
Quantum Physics
The continuous scaling of metal-oxide-semiconductor field-effect transistors (MOSFETs) has led to device geometries where charged carriers are increasingly confined to ever smaller channel cross sections. This development is associated with reduced screening of long-range Coulomb interactions. To accurately predict the behavior of such ultra-scaled devices, electron-electron (e-e) interactions must be explicitly incorporated in their quantum transport simulation. In this paper, we present an \textit{ab initio} atomistic simulation framework based on density functional theory, the non-equilibrium Green's function formalism, and the self-consistent GW approximation to perform this task. The implemented method is first validated with a carbon nanotube test structure before being applied to calculate the transfer characteristics of a silicon nanowire MOSFET in a gate-all-around configuration. As a consequence of e-e scattering, the energy and spatial distribution of the carrier and current densities both significantly change, while the on-current of the transistor decreases owing to the Coulomb repulsion between the electrons. Furthermore, we demonstrate how the resulting bandgap modulation of the nanowire channel as a function of the gate-to-source voltage could potentially improve the device performance. To the best of our knowledge, this study is the first one reporting large-scale atomistic quantum transport simulations of nano-devices under non-equilibrium conditions and in the presence of e-e interactions within the GW approximation.
title Electron-Electron Interactions in Device Simulation via Non-equilibrium Green's Functions and the GW Approximation
topic Mesoscale and Nanoscale Physics
Quantum Physics
url https://arxiv.org/abs/2412.12986