Klemen Kovač (Avtor), Janez Bonča (Avtor)

Povzetek

Using an efficient variational exact diagonalization method, we computed the electron removal spectral function within the framework of the Holstein-Hubbard model containing two electrons with opposite spins coupled to dispersive quantum optical phonons. We focus on how the interplay between the electron-phonon coupling and on-site Coulomb repulsion shapes the spectral function, a quantity directly relevant to angle-resolved photoemission spectroscopy (ARPES). Tuning the strengths of the electron-phonon coupling and the Hubbard interaction allows us to examine the evolution of the spectral properties of the system as it crosses over from a bound bipolaron to separate polarons. We find that phonon dispersion plays an important role: It substantially redistributes the spectral weight across the low- and the high-energy features and controls the emergence and the structure of distinct multiphonon continua. In regimes of strong electron-phonon coupling and low Coulomb repulsion, the spectral function exhibits a broad distribution reflecting bound bipolaronic states. Increasing the Coulomb repulsion weakens bipolaron binding, shifts the primary quasiparticle peak closer to polaronic behavior and confines the spectral weight near the Brillouin-zone center. Our results provide a framework for interpreting ARPES measurements in systems where phonon–mediated attraction competes with direct Coulomb repulsion.

Ključne besede

fizika kondenzirane snovi;kvantna fizika;optični fononi;polaroni;Holsteinov model;Hubbardov model;elektronsko-fononska sklopitev;condensed matter physics;quantum physics;optical phonons;polarons;Holstein model;Hubbard model;electron-phonon coupling;

Podatki

Jezik: Angleški jezik
Leto izida:
Tipologija: 1.01 - Izvirni znanstveni članek
Organizacija: UL FMF - Fakulteta za matematiko in fiziko
UDK: 538.9
COBISS: 229057027 Povezava se bo odprla v novem oknu
ISSN: 2469-9950
Št. ogledov: 109
Št. prenosov: 35
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Slovenski jezik
Sekundarne ključne besede: fizika kondenzirane snovi;kvantna fizika;optični fononi;polaroni;Holsteinov model;Hubbardov model;elektronsko-fononska sklopitev;
Vrsta dela (COBISS): Članek v reviji
Strani: str. 115133-1-115133-12
Letnik: ǂVol. ǂ111
Zvezek: ǂiss. ǂ11
Čas izdaje: 2025
DOI: 10.1103/PhysRevB.111.115133
ID: 26057776