Turkish Journal of Physics
Abstract
We present a method for calculating the effective mass and quasiparticle weight of a Landau Fermi liquid using time-ordered Green’s functions and a Wick rotation to the imaginary frequency axis. This technique simplifies the evaluation of self-energy derivatives by ensuring analytic properties compatible with contour deformations. We apply the method to the electron gas in both two and three spatial dimensions within the random phase approximation (RPA), and derive explicit expressions for the static and dynamic contributions to the self-energy. Our results confirm known limits at weak coupling and offer an accurate and transparent route to evaluate effective mass and quasiparticle weight, with clear extensions possible for systems including vertex corrections or local-field effects and band-gap renormalization.
DOI
10.55730/1300-0101.2793
Keywords
Fermi liquid theory, effective mass, quasiparticle weight, self-energy, Coulomb interaction, complex frequency
First Page
279
Last Page
293
Publisher
The Scientific and Technological Research Council of Türkiye (TÜBİTAK)
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
KESER, A, & SUSHKOV, O. P (2025). Quasiparticle weight and effective mass of the Landau liquid from the complex-frequency formalism. Turkish Journal of Physics 49 (6): 279-293. https://doi.org/10.55730/1300-0101.2793
