Vertex-corrected perturbation theory for the electron-phonon problem with nonconstant density of states
|Title||Vertex-corrected perturbation theory for the electron-phonon problem with nonconstant density of states|
|Publication Type||Journal Article|
|Year of Publication||1998|
|Authors||Freericks, J. K., Zlatic V., Chung W. K., and Jarrell M.|
|Journal||Physical Review B|
A series of weak-coupling perturbation theories that include the lowest-order vertex corrections are applied to the attractive Holstein model in infinite dimensions. The approximations are chosen to reproduce the iterated perturbation theory in the limit of half-filling and large phonon frequency (where the Holstein model maps onto the Hubbard model). Comparison is made with quantum Monte Carlo solutions to test the accuracy of different approximation schemes.