Introduction

Download the nextnano.MSB software

Documentation of the nextnano.MSB software

This manual describes the nextnano.MSB software, an NEGF quantum transport code based on the MSB method.

The nextnano.MSB software has been developed to simulate Quantum Cascade Lasers (QCLs) and Resonant Tunneling Diodes (RTDs). The software calculates current-voltage characteristics and gain.

Electron and current density of a QCL

Calculated electron and current density of a Quantum Cascade Laser

This software is based on a novel quantum transport method that follows the nonequilibrium Green’s function (NEGF) framework but sidesteps any self-consistent calculation of lesser self-energies by replacing them by a quasi-equilibrium expression. This method generalizes the so-called Büttiker probe model but takes into account all relevant individual scattering mechanisms. It is orders of magnitude more efficient than a fully self-consistent nonequilibrium Green’s function calculation for realistic devices, yet accurately reproduces the results of the latter method. This method opens the path towards realistic three-dimensional quantum transport calculations.

MSB is the acronym of the Multi-Scattering Büttiker probe model.

The code can be executed using the nextnanomat software. The results of the calculation can be visualized using the nextnanomat software.

Calculated gain of a QCL

Calculated gain of a Quantum Cascade Laser

Which scattering mechanisms are included?

  • Longitudinal polar-optical phonon scattering (polar LO phonon scattering).

  • Acoustic phonon scattering which includes some kind of interface roughness scattering. The latter is intrinsically included.

Where can I find some background on the implemented physics?

The MSB method is decribed in the following publications: [GreckOE2015], [GreckIWCE2010], [GreckPhD2012]

Copyright information

The nextnano.MSB software has been developed by Dr. Peter Greck for the nextnano GmbH. It is written in C++.