Dynamically screened vertex correction to GW
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
Published in
Physical Review BDate
2020Copyright
©2020 American Physical Society
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.
...
Publisher
American Physical SocietyISSN Search the Publication Forum
2469-9950Publication in research information system
https://converis.jyu.fi/converis/portal/detail/Publication/41675008
Metadata
Show full item recordCollections
Related funder(s)
Research Council of FinlandFunding program(s)
Academy Project, AoFAdditional information about funding
Thework has been performed under the Project HPC-EUROPA3(INFRAIA-2016-1-730897), with the support of the EC Re-search Innovation Action under the H2020 Programme; inparticular, Y.P. gratefully acknowledges the computer re-sources and technical support provided the CSC-IT Centerfor Science (Espoo, Finland). Y.P. acknowledges support ofDeutsche Forschungsgemeinschaft (DFG), Collaborative Re-search Centre SFB/TRR 173 “Spin+X.” G.S. acknowledgesfunding from MIUR PRIN Grant No. 20173B72NB and fromINFN17_nemesys project. R.v.L. likes to thank the Academyof Finland for support under Grant No. 317139. ...License
Related items
Showing items with similar title or keywords.
-
Many-body Green's function theory of electrons and nuclei beyond the Born-Oppenheimer approximation
Härkönen, Ville J.; van Leeuwen, Robert; Gross, E. K. U. (American Physical Society, 2020)The method of many-body Green's functions is developed for arbitrary systems of electrons and nuclei starting from the full (beyond Born-Oppenheimer) Hamiltonian of Coulomb interactions and kinetic energies. The theory ... -
Magnomechanics in suspended magnetic beams
Kansanen, Kalle S. U.; Tassi, Camillo; Mishra, Harshad; Sillanpää, Mika A.; Heikkilä, Tero T. (American Physical Society (APS), 2021)Cavity optomechanical systems have become a popular playground for studies of controllable nonlinear interactions between light and motion. Owing to the large speed of light, realizing cavity optomechanics in the microwave ... -
Signatures and characterization of dominating Kerr nonlinearity between two driven systems with application to a suspended magnetic beam
Sokolov, Andrii M.; Heikkilä, Tero T. (American Physical Society (APS), 2024)We consider a model of two harmonically driven damped harmonic oscillators that are coupled linearly and with a cross-Kerr coupling. We show how to distinguish this combination of coupling types from the case where a ... -
Numerical simulation of free dissipative open quantum system and establishment of a formula for π
Agasti, Souvik (American Institute of Physics, 2020)We transform the system/reservoir coupling model into a one-dimensional semi-infinite discrete chain with nearest neighbor interaction through a unitary transformation, and, simulate the dynamics of free dissipative open ... -
Domain wall motion in a diffusive weak ferromagnet
Aikebaier, Faluke; Heikkilä, Tero T. (American Physical Society, 2020)We study the domain wall motion in a disordered weak ferromagnet, induced by injecting a spin current from a strong ferromagnet. Starting from the spin-diffusion equation describing the spin accumulation in the weak ...