Abstract
We present a nontrivial model system of interacting electrons that can be solved analytically in the approximation. We obtain the particle number from the Green’s function strictly analytically, and prove that there is a genuine violation of particle number conservation if the self-energy is calculated non-self-consistently from a zeroth order Green’s function, as done in virtually all practical implementations. We also show that a simple shift of the self-energy that partially restores self-consistency reduces the numerical deviation significantly.
- Received 5 February 1997
DOI:https://doi.org/10.1103/PhysRevB.56.3528
©1997 American Physical Society