Hi Rudolf, In tkwant the wavefunction approach is used instead of non-equilibrium Green functions. This provides better scalability in both time and system size. Non-equilibrium densities and currents can be obtained by evolving kwant operators in time. The Green functions (if needed) can be also obtained by integrating the wavefunctions over energy. For more details you can have a look to the Weston’s thesis (book) [1] (mainly Chapter 2 and 3) as well as the tkwant tutorials. Regards,
* J. Weston, Numerical Methods for Time-Resolved Quantum Nanoelectronics, Springer (2017)
