Self-energies in Atomistic Quantum Transport for Energy Transfer at Irregular Interfaces

The nonequilibrium Green's function (NEGF) method has become an integral part of computational nanodevice R&D. The reliability of the NEGF method is intimately coupled to the quality of its self-energies as they describe incoherent scattering of electrons on impurities, various types of phonons, and any type of irregularity in the device environment. In this work, we emphasize the impact of approximations on self-energies and ways to avoid them, including approximations on the nonlocality of long-range scattering, the Kramers-Kronig relation of state broadenings and shifts, and the impact of idealized periodicity assumptions in the device vicinity.