A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Dynamically screened vertex correction to GW (2020)
Pavlyukh, Y., Stefanucci, G., & van Leeuwen, R. (2020). Dynamically screened vertex correction to GW. Physical Review B, 102(4), Article 045121. https://doi.org/10.1103/PhysRevB.102.045121
JYU-tekijät tai -toimittajat
Julkaisun tiedot
Julkaisun kaikki tekijät tai toimittajat: Pavlyukh, Yaroslav; Stefanucci, Gianluca; van Leeuwen, Robert
Lehti tai sarja: Physical Review B
ISSN: 2469-9950
eISSN: 2469-9969
Julkaisuvuosi: 2020
Volyymi: 102
Lehden numero: 4
Artikkelinumero: 045121
Kustantaja: American Physical Society
Julkaisumaa: Yhdysvallat (USA)
Julkaisun kieli: englanti
DOI: https://doi.org/10.1103/PhysRevB.102.045121
Julkaisun avoin saatavuus: Ei avoin
Julkaisukanavan avoin saatavuus:
Julkaisu on rinnakkaistallennettu (JYX): https://jyx.jyu.fi/handle/123456789/71363
Rinnakkaistallenteen verkko-osoite (pre-print): https://arxiv.org/abs/2004.05344
Tiivistelmä
Diagrammatic perturbation theory is a powerful tool for the investigation of interacting many-body systems, the self-energy operator Sigma encoding all the variety of scattering processes. In the simplest scenario of correlated electrons described by the GW approximation for the electron self-energy, a particle transfers a part of its energy to neutral excitations. Higher-order (in screened Coulomb interaction W) self-energy diagrams lead to improved electron spectral functions (SFs) by taking more complicated scattering channels into account and by adding corrections to lower order self-energy terms. However, they also may lead to unphysical negative spectral functions. The resolution of this difficulty has been demonstrated in our previous works. The main idea is to represent the self-energy operator in a Fermi golden rule form which leads to a manifestly positive definite SF and allows for a very efficient numerical algorithm. So far, the method has only been applied to the three-dimensional electron gas, which is a paradigmatic system, but a rather simple one. Here we systematically extend the method to two dimensions including realistic systems such as monolayer and bilayer graphene. We focus on one of the most important vertex function effects involving the exchange of two particles in the final state. We demonstrate that it should be evaluated with the proper screening and discuss its influence on the quasiparticle properties.
YSO-asiasanat: tiiviin aineen fysiikka; kvanttifysiikka; approksimointi
Liittyvät organisaatiot
Hankkeet, joissa julkaisu on tehty
- Nya metoder i kvantmekanisk mångkroppsteori
- Van Leeuwen, Robertus
- Suomen Akatemia
OKM-raportointi: Kyllä
Raportointivuosi: 2020
JUFO-taso: 2