Work

Charge collective modes in correlated electron systems: Plasmons beyond the random phase approximation

Year: 2024

Type: article

Abstract: Elucidating the impact of strong electronic interactions on the collective excitations of metallic systems has been of longstanding interest, mainly due to the inadequacy of the random phase approximation (RPA) in the strongly correlated regime. Here, we adopt our newly developed radial Kotliar and Ruckenstein slave boson representation to analyze the charge excitation spectrum of a Hubbard model, extended with long range interactions. Working on the face centered cubic lattice, at half filling, and in different coupling regimes ranging from uncorrelated to the metal-to-insulator transition, we compare our results to conventional RPA as a benchmark. We focus on the influence of the local and long range couplings on the particle-hole excitation continuum and the plasmon and upper Hubbard band collective modes. Beyond the weak coupling regime, we find numerous quantitative and even qualitative discrepancies between our method and standard RPA. Our work thus deepens the understanding of charge collective modes in correlated systems and lays the foundations for future studies of a broad series of materials.

Source: Physical review. B./Physical review. B

DOI: 10.1103/physrevb.110.115143

Authors: Loïc Philoxene, Vu Hung Dao, Raymond Frésard

Institutions: Centre National de la Recherche Scientifique, École Nationale Supérieure d'Ingénieurs de Caen, Normandie Université, Laboratoire de Cristallographie et Sciences des Matériaux

Language: English

Topic: Physics of Superconductivity and Magnetism

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Agence Nationale de la Recherche, Région Normandie

Award: Lone Pair Thermoelectric Sulfur Based Compounds