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Applicability and limitations of cluster perturbation theory for Hubbard models

Enenkel, Nicklas 1; Garst, Markus ORCID iD icon 1,2; Schmitteckert, Peter
1 Institut für Theoretische Festkörperphysik (TFP), Karlsruher Institut für Technologie (KIT)
2 Institut für QuantenMaterialien und Technologien (IQMT), Karlsruher Institut für Technologie (KIT)

Abstract:

We present important use cases and limitations when considering results obtained from cluster perturbation theory (CPT). CPT combines the solutions of small individual clusters of an infinite lattice system with the Bloch theory of conventional band theory to provide an approximation for the Green’s function in the thermodynamic limit. To this end, we are investigating single-band and multi-band Hubbard models in 1D and 2D systems. A special interest is taken in the supposed pseudogap regime of the 2D square lattice at half-filling and intermediate interaction strength $(U≤3t)$ as well as the metal–insulator transition. We point out that the finite-size level spacing of the cluster limits the resolution of spectral features within CPT. This restricts the investigation of asymptotic properties of the metal–insulator transition, as it would require much larger cluster sizes that are beyond computational capabilities.


Verlagsausgabe §
DOI: 10.5445/IR/1000163576
Veröffentlicht am 30.10.2023
Originalveröffentlichung
DOI: 10.1140/epjs/s11734-023-00976-5
Scopus
Zitationen: 3
Web of Science
Zitationen: 3
Dimensions
Zitationen: 5
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für QuantenMaterialien und Technologien (IQMT)
Institut für Theoretische Festkörperphysik (TFP)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2023
Sprache Englisch
Identifikator ISSN: 1951-6355, 1951-6401
KITopen-ID: 1000163576
HGF-Programm 47.11.02 (POF IV, LK 01) Emergent Quantum Phenomena
Erschienen in The European Physical Journal Special Topics
Verlag Springer-Verlag
Band 232
Seiten 3495–3504
Vorab online veröffentlicht am 27.09.2023
Nachgewiesen in Web of Science
Dimensions
Scopus
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