Luttinger surface and exchange splitting induced by ferromagnetic fluctuations

Fuente: arXiv
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Main Authors: Kitatani, Motoharu, Nomura, Yusuke, Sakai, Shiro, Arita, Ryotaro
Format: Preprint
Published: 2025
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author Kitatani, Motoharu
Nomura, Yusuke
Sakai, Shiro
Arita, Ryotaro
author_facet Kitatani, Motoharu
Nomura, Yusuke
Sakai, Shiro
Arita, Ryotaro
contents Ferromagnetism in the single-orbital Hubbard model, which contains only local Coulomb repulsion and no explicit ferromagnetic exchange interactions, has been extensively studied. However, how the associated fluctuations influence the electronic properties near the transition remains a fundamental issue. Here, by applying the dynamical vertex approximation (D$Γ$A) to single-orbital systems with a partially flat band dispersion, we demonstrate that finite-correlation-length ferromagnetic fluctuations generate an emergent Luttinger surface and drive a Fermi surface expansion reminiscent of exchange splitting, even without magnetic order. We further derive an analytical expression that reproduces these effects, clarifying the microscopic origin for fluctuation-driven exchange splitting in correlated electron systems.
format Preprint
id arxiv_https___arxiv_org_abs_2509_21034
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Luttinger surface and exchange splitting induced by ferromagnetic fluctuations
Kitatani, Motoharu
Nomura, Yusuke
Sakai, Shiro
Arita, Ryotaro
Strongly Correlated Electrons
Ferromagnetism in the single-orbital Hubbard model, which contains only local Coulomb repulsion and no explicit ferromagnetic exchange interactions, has been extensively studied. However, how the associated fluctuations influence the electronic properties near the transition remains a fundamental issue. Here, by applying the dynamical vertex approximation (D$Γ$A) to single-orbital systems with a partially flat band dispersion, we demonstrate that finite-correlation-length ferromagnetic fluctuations generate an emergent Luttinger surface and drive a Fermi surface expansion reminiscent of exchange splitting, even without magnetic order. We further derive an analytical expression that reproduces these effects, clarifying the microscopic origin for fluctuation-driven exchange splitting in correlated electron systems.
title Luttinger surface and exchange splitting induced by ferromagnetic fluctuations
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2509.21034