Welcome to fuNEGF’s documentation!

The fuNEGF project on GitHub is a Python package for the calculation of the electronic transport properties of nanostructures using the Non-Equilibrium Green’s Function (NEGF) formalism for educational purposes. Limited to a 1D linear chain for now.

Quickstart

pip install fuNEGF

and

git clone https://github.com/liborsold/fuNEGF.git

to execute the ./examples/one-dimensional_channel.ipynb Jupyter notebook and see an example of calculating the NEGF transmission and chemical potential in the presence of impurities.

The impurities acts as quantum resistors, causing a drop in the chemical potential (occupation number). Without phase relaxation mechanisms, this might be difficult to see. Additionally, momentum relaxation mechanisms spread the chemical potential decrease into the clean wire region.

Strong localized impurities reduce the transmission function from its clean limit \(T(E) = 1.0 = \mathrm{const.}\) to half of this value. With weak, randomly distributed impurities, the transmission starts to resemble the clean limit again.

Navigation

• Theory
  • Non-Equilibrium Green’s functions (NEGF)
  • Linear Chain Model
• Example
  • 1. Linear-chain tight-binding Hamiltonian
  • 2. Impurity potential
  • 3. Chemical potential with impurities
    • 3.1. No relaxation
    • 3.2. Phase relaxation
    • 3.3. Phase and momentum relaxation
  • 4. Transmission function
    • 4.1. Single impurity
    • 4.2. Different impurity distributions
• Modules
  • fuNEGF.models
• Classes
  • LinearChain
    • LinearChain.G_R_fun()
    • LinearChain.Greens_functions_solver()
    • LinearChain.add_H_impurity()
    • LinearChain.compare_dispersion_analytic_vs_numerical()
    • LinearChain.construct_H()
    • LinearChain.plot_occupation()
    • LinearChain.plot_onsite_energy()
    • LinearChain.plot_transmission()

Indices and tables

• Index

• Module Index

• Search Page