Severe Fermi Surface Reconstruction at a Metamagnetic Transition inCa2−xSrxRuO4(for0.2≤x

Abstract

We report an electrical transport study in Ca2-xSrxRuO4 single crystals at high magnetic fields (B). For x=0.2, the Hall constant Rxy decreases sharply at an anisotropic metamagnetic transition, reaching its value for Sr2RuO4 at high fields. A sharp decrease in the coefficient of the resistivity T2 term and a change in the structure of the angular magnetoresistance oscillations for B rotating in the planes confirms the reconstruction of the Fermi surface. Our observations and local-density-approximation calculations indicate a strong dependence of the Fermi surface on Ca concentration and suggest the coexistence of itinerant and localized electronic states in single layered ruthenates.

Interplay of metamagnetic and structural transitions in Ca2-xSrxRuO4

“…In this scenario the experimental observation of the 1/2 effective spin is assigned to the localized hole in the {α, β} bands. Angular magnetoresistance oscillations measurements [13] indeed show a strong dependence of the Fermi surface on the Ca concentration which is consistent with the scenario of coexisting itinerant and localized d-electronic states. Furthermore, from the theoretical point of view, there is by now a consensus that an OSMT can in principle occur in multi-band Hubbard models under rather general conditions [14,15,16,17,18,19,20,21,22].…”

Magnetic excitations in the metallic single-layer ruthenates Ca2−xSrxRuOSteffens1, Friedt2, Sidis3 et al. 2011Phys. Rev. BSelf Cite

“…[40][41][42] Wang et al 40 report a holelike γ band for x = 0.5, in agreement with the theory and magnetoresistance oscillations. 43 However, for even smaller Sr content, in the doping range where the tilt distortion is also present, x = 0.2, Neupane et al 42 report the complete disappearance of the γ -Fermi surface sheet, whereas Shimoyamada et al 41 find that all bands cross the Fermi level for this concentration. All three ARPES studies [40][41][42] clearly document that the d xy states are strongly renormalized.…”

Quantum interference and weak localization effects in the interlayer magnetoresistance of layered metals

“…which implies a decrease in the resistivity, which grows as B Ќ increases, i.e., as deviates from 2 . In consequence, there will be a peak above the background resistance at = 2 .…”

“…-(BEDT-TTF) 2 Cu(NCS) 2 The magnitude and temperature dependence of the inelastic-scattering rate in -͑BEDT-TTF͒ 2 Cu͑NCS͒ 2 was recently determined using AMRO. 13 The data was fit to…”