Fermi Surface Expansion above Critical Temperature in a Hund Ferromagnet

Yusuke Nomura, Shiro Sakai, Ryotaro Arita

Research output: Contribution to journalArticlepeer-review

Abstract

Using a cluster extension of the dynamical mean-field theory, we show that strongly correlated metals subject to Hund's physics exhibit significant electronic structure modulations above magnetic transition temperatures. In particular, in a ferromagnet having a large local moment due to Hund's coupling (Hund's ferromagnet), the Fermi surface expands even above the Curie temperature (TC) as if a spin polarization occurred. Behind this phenomenon, effective "Hund's physics"works in momentum space, originating from ferromagnetic fluctuations in the strong-coupling regime. The resulting significantly momentum-dependent (spatially nonlocal) electron correlations induce an electronic structure reconstruction involving a Fermi surface volume change and a redistribution of the momentum-space occupation. Our finding will give a deeper insight into the physics of Hund's ferromagnets above TC.

Original languageEnglish
Article number206401
JournalPhysical review letters
Volume128
Issue number20
DOIs
Publication statusPublished - 2022 May 20
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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