LCBB-Package Documentation

Welcome to the manual for the Linear combination of Bulk Bands (LCBB) package, a program for computing the electronic structure of semiconductor structures such as quantum Dots. This tutorial covers the generation of the nanostructures (geom), the relaxation of the atomic positions (vff), the calculation of the single-particle electronic structure (slcbb), the calculation of the direct and exchange Coulomb integrals (cmat_atomistic), the calculation of the many-body wave functions (mxci), the calculation of the optical properties and lifetimes and the use of "analysis tools" such as wave function imaging, correlation functions etc...

Contents

This documentation is divided into the following sections:

• Introduction:

• Installation: How to install and compile LCBB and related programs.

• Geom tutorial How to generate the quantum dots. Different shapes are possible with arbitrary sizes and compositions/composition profiles.

• VFF tutorial How to relax the atomic positions generated by VFF.

• Band Offset calculations How to estimate the energy of the lowest conduction and the three upper valence bands in semiconductors. This is a ``helper-program'' that may be used to estimate the energetic position and symmetry (e.g., hh,lh,so) of confined electron and hole levels.

• SLCBB Tutorial: In this section, we introduce the use of SLCBB to compute selected eigen states of a semiconductor structure. Simple examples illustrate the basic usage of the program.
  • Input files
  • A first calculation (8 atom InP cubic cell)
  • Parabolic confinement
  • Output files
  • An atomic superlattice (alloy effects)
  • A Quantum dot Calculation (alloy effects)

• SLCBB-Tools Tutorial: This section describes the different tools available to analyse and visualize the single-particle wave functions.

• cmat_atomistic Tutorial : How to calculate the Coulomb integrals from the single-particle wave functions generated by slcbb.

• mxci Tutorial : How to obtain correlated many-body wave functions knowing the Coulomb Integrals.

• Optical Properties and Lifetimes: How to calclulate optical properties from the many-body wave functions.
  • Running the dipole code for the single-particle wave funcitons.
  • Required CI calculations
  • Running the dipole code for the CI wave functions
  • Calculating the oscillator Strength and the lifetimes

• Calculation of the pair correlation function: A derivation of the expressions is available for 2 electrons.
• Calculation of nsom:  A description how to run the code nsom
  
• Basic reference to CVS: These are just the few commands I tend to use.

• User Reference: A listing of the various input parameters and description of input files.