arXiv:1908.08957 · Physical review. B./Physical review. B
Coupled electron-impurity and electron-phonon systems as trivial non-Fermi liquids
Donovan Buterakos, S. Das Sarma
Abstract
We consider an electron gas, both in two (2D) and three (3D) dimensions, interacting with quenched impurities and phonons within leading order finite-temperature many-body perturbation theories, calculating the electron self-energies, spectral functions, and momentum distribution functions at finite temperatures. The resultant spectral function is in general highly non-Lorentzian, indicating that the system is not a Fermi liquid in the usual sense. The calculated momentum distribution function cannot be approximated by a Fermi function at any temperature, providing a rather simple example of a non-Fermi liquid with well-understood properties.