Splitting of electronic spectrum in paramagnetic phase of itinerant ferromagnets and altermagnets

Abstract

We study self-energy effects induced by strong magnetic fluctuations in the paramagnetic phase of strongly-correlated itinerant magnets within the density functional theory combined with the dynamical mean field theory (DFT+DMFT approach) and its non-local extension. We show that both local and non-local magnetic correlations yield a splitting of the electronic spectrum in the paramagnetic phase, such that it closely resembles the DFT band structure in the ordered phase. We demonstrate these effects on $\alpha$-iron, half-metal CrO${}_2$, van der Waals material CrTe${}_2$, and altermagnet CrSb. Although the obtained split bands do not possess a certain spin projection, their splitting suppresses spectral weight at the Fermi level. Even when originating from local magnetic correlations, the splitting is strongly momentum dependent as a consequence of the orbital selectivity of non-quasiparticle states. The relative importance of non-local vs. local correlations depends on the proximity to half filling of $d$ states: closer to half filling, the role of local correlations increases.

7+6 pages, 5+3 figures. Accepted as Phys. Rev. B Letter

References in corpus (25)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Dynamical vertex approximation - a step beyond dynamical mean field theory
• Spin freezing transition and non-Fermi-liquid self-energy in a 3-orbital model
• Large band-splitting in $g$-wave type altermagnet CrSb
• Three-dimensional mapping of the altermagnetic spin splitting in CrSb
• Local magnetic moments in iron and nickel at ambient and Earth's core conditions
• Quasiparticle Mass Enhancement and Temperature Dependence of the Electronic Structure of Ferromagnetic SrRuO3 Thin Films
• Observation of Spin Splitting in Room-Temperature Metallic Antiferromagnet CrSb
• Ab initio dynamical vertex approximation
• $i$QIST: An open source continuous-time quantum Monte Carlo impurity solver toolkit
• Magnetism of iron and nickel from rotationally invariant Hirsch-Fye quantum Monte Carlo calculations
• Nonlocal correlations induced by Hund's coupling: a cluster DMFT study
• $i$QIST v0.7: An open source continuous-time quantum Monte Carlo impurity solver toolkit
• Observation of spin-dependent dual ferromagnetism in perovskite ruthenates
• Rotationally-Invariant Exchange Interaction: The Case of Paramagnetic Iron
• Exchange interactions in iron and nickel: DFT+DMFT study in paramagnetic phase
• Electronic self-energy and triplet pairing fluctuations in the vicinity of a ferromagnetic instability in 2D systems: the quasistatic approach
• Fermi surface expansion above critical temperature in a Hund ferromagnet
• Linear response theories for interatomic exchange interactions
• Unusual ferromagnetic band evolution and high Curie temperature in monolayer 1T-CrTe2 on bilayer graphene
• Magnetic properties of half metal from the paramagnetic phase: DFT+DMFT study of exchange interactions in CrO${}_2$
• Magnetic properties of monolayer, multilayer, and bulk CrTe${}_2$
• Unambiguous fluctuation decomposition of the self-energy: pseudogap physics beyond spin fluctuations
• Exchange interactions in itinerant magnets: the effects of local particle-hole irreducible vertex corrections and SU(2) symmetry of Hund interaction

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