Quantum Energy-Transport and Drift-Diffusion models

نویسندگان

  • Pierre Degond
  • Florian Méhats
  • Christian Ringhofer
چکیده

We show that Quantum Energy-Transport and Quantum Drift-Diffusion models can be derived through diffusion limits of a collisional Wigner equation. The collision operator relaxes to an equilibrium defined through the entropy minimization principle. Both models are shown to be entropic and exhibit fluxes which are related with the state variables through spatially non-local relations. Thanks to an ~ expansion of these models, ~2 perturbations of the Classical Energy-Transport and Drift-Diffusion models are found. In the DriftDiffusion case, the quantum correction is the Bohm potential and the model is still entropic. In the Energy-Transport case however, the quantum correction is a rather complex expression and the model cannot be proven entropic.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

2D Simulation Models for Quantum Mechanical Effects

ductor devices. A self consistent Schrodinger – Poisson solver allows calculation of bound state energies and associated carrier wave functions self consistently with electrostatic potential. Schrodinger solvers can be combined with Non-equilibrium Green’s Function (NEGF) Approach in order to model ballistic quantum transport in 2D or cylindrical devices with strong transverse confinement. An a...

متن کامل

Quantum Hydrodynamic models derived from the entropy principle

In this work, we give an overview of recently derived quantum hydrodynamic and diffusion models. A quantum local equilibrium is defined as a minimizer of the quantum entropy subject to local moment constraints (such as given local mass, momentum and energy densities). These equilibria relate the thermodynamic parameters (such as the temperature or chemical potential) to the densities in a non-l...

متن کامل

Chapter 1 Classical Device Modeling

In this chapter an overview of classical device modeling will be given. The first section is dedicated to the derivation of the Drift–Diffusion Transport model guided by physical reasoning. How to incorporate Fourier’s law to add a dependence on temperature gradients into the description, is presented. Quantum mechanical effects relevant for small devices are approximately covered by quantum co...

متن کامل

Quantum–Corrected Drift–Diffusion Models for Transport in Semiconductor Devices

In this article, we propose a unified framework for Quantum–Corrected Drift–Diffusion (QCDD) models in nanoscale semiconductor device simulation. QCDD models are presented as a suitable generalization of the classical Drift–Diffusion (DD) system, each particular model being identified by the constitutive relation for the quantum–correction to the electric potential. We examine two special, and ...

متن کامل

Two spinorial drift-diffusion models for quantum electron transport in graphene

Two drift-diffusion models for the quantum transport of electrons in graphene, which account for the spin degree of freedom, are derived from a spinorial Wigner equation with relaxation-time or massand spin-conserving matrix collision operators using a Chapman-Enskog expansion around the thermal equilibrium. Explicit models are computed by assuming that both the semiclassical parameter and the ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2004