Transition offelectron nature from itinerant to localized: Metamagnetic transition inCeRu2Si2

Abstract

We report the measurements of the de Haas-van Alphen (dHvA) effect for field ranges below and above the metamagnetic transition field (//m) in CeRu2Si2. The dHvA frequency branches and the effective masses ranging from 1.5A^7O to 120mo observed below Hm agree with the predictions of the itinerant / electron model, whereas those above Hm can be explained well with the localized / electron model. All the dHvA frequencies change abruptly around Hm-The effective masses decrease considerably around Hm and then continue to decrease with increasing field.

Fermi Surface Properties, Metamagnetic Transition and Quantum Phase Transition of CeRu2Si2 and Its Alloys Probed by the dHvA Effect

“…17(b). 1,106,107,111,117 The effective mass of the ω oscillation is spin dependent and the other oscillation with the heavier mass may have the effective mass of the order of several tens of m 0 .…”

Mean-field study of the heavy-fermion metamagnetic transition

“…4,5 Recent experiments on CeRu 2 Si 2 , however, suggest that the localization scenario might not be appropriate. 6 This was already pointed out in Ref.…”

“…7, in which static magnetization measurements ruled out the possibility of a first order phase transition, at odds with the existent de Haas-van Alphen measurements. 5 On the basis of Hall effect and magnetoresistance measurements, the authors of Ref. 6 proposed that the MMT anomalies result from a continuous evolution of the Fermi surface in which the spin-split sheet corresponding to the heaviest electrons shrinks to a point.…”

Electronic structure ofCeRu2X2(X=Si,Yano1, Sekiyama2, Fujiwara3 et al. 2008Phys. Rev. BSelf Cite515210View full textAdd to dashboardCite

“…So far, CeRu 2 Si 2 has eagerly been studied in order to elucidate the mechanism of the metamagnetic transition which occurs at H m ∼ 7.7 T. 15,16 According to the de Haas-van Alphen (dHvA) studies, 17 the Fermi surface (FS) of CeRu 2 Si 2 approaches to that of LaRu 2 Si 2 above H m due to the localization of the 4f electrons. However, the dHvA results of CeRu 2 Si 2 can not fully be explained by the band structure calculations under H < H m .…”