Band-Selective Modification of the Magnetic Fluctuations in Sr2RuO4: Study of Substitution Effects

dc.creatorKikugawa, N.
dc.creatorBergemann, C.
dc.creatorMackenzie, A. P.
dc.creatorMaeno, Y.
dc.date2002-11-13
dc.date2004-04-30
dc.date.accessioned2026-07-07T02:48:09Z
dc.date.available2026-07-07T02:48:09Z
dc.descriptionWe report a study of magnetic, thermal, and transport properties of La(3+) substituted Sr2RuO4, performed in order to investigate the effects of additional electron doping in this correlated metal. A gradual enhancement of the electronic part of specific heat and a more drastic increase of the static magnetic susceptibility were observed in Sr(2-y)La(y)RuO(4) with increasing y. Furthermore, the quasi-two-dimensional Fermi-liquid behavior seen in pure Sr2RuO4 breaks down near the critical concentration y ~ 0.20. Combined with a realistic tight-binding model with rigid-band shift of Fermi level, the enhancement of the density of states can be ascribed to the elevation of the Fermi energy toward a van Hove singularity of the thermodynamically dominant γFermi-surface sheet. On approaching the van Hove singularity, the effective nesting-vector of the γband shrinks and further enhances the susceptibility near the wave vector q ~ 0. We attribute the non-Fermi-liquid behavior to two-dimensional ferromagnetic fluctuations with short range correlations at the van Hove singularity. The observed behavior is in sharp contrast to that of Ti(4+) substitution in Sr2RuO4 which enhances antiferromagnetic fluctuations and subsequently induces incommensurate magnetic ordering associated with the nesting between the other Fermi-surface sheets (αand β). We thus establish that substitution of appropriate chemical dopants can band-selectively modify the spin-fluctuation spectrum in the spin-triplet superconductor Sr2RuO4.
dc.description8 pages, 7 figures
dc.identifierhttps://arxiv.org/abs/cond-mat/0211248
dc.identifierhttp://arxiv.org/abs/cond-mat/0211248
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/20290
dc.subjectStrongly Correlated Electrons
dc.subjectSuperconductivity
dc.titleBand-Selective Modification of the Magnetic Fluctuations in Sr2RuO4: Study of Substitution Effects
dc.typetext

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