Sometimes, depending on the background knowledge, it is useful to think in terms of the molecular orbital theory. In this case, the conduction band can be thought as a bunch of LUMO orbitals, while the valence band is a bunch of HOMO orbitals at zero Kelvins.
Thanks all for replies. Einstein Mcfly, you are right. Indeed, I am using Runge-Kutta solver. However, It seems, the numerical procedure is working correct. Could the problem be in the constant dephasing time which I have added artificiallyv (it is not following from the density matrix...
Hello everyone,
I am trying to solve time-dependent Liouville-von-Neumann equations for the dynamics of an electron traveling between several coherently coupled states with constant dephasing time. I was very surprised receiving negative values for diagonal elements of the density matrix in...