Fermi surface topology and hot spot distribution in the Kondo lattice systemCeB6

Abstract

Rare-earth hexaborides have attracted a considerable attention recently in connection to variety of correlated phenomena including heavy fermions, superconductivity and low temperature magnetic phases. Here, we present high-resolution angle-resolved photoemission spectroscopy studies of trivalent CeB 6 and divalent BaB 6 rare-earth hexaborides. We find that the Fermi surface electronic structure of CeB 6 consists of large oval-shaped pockets around the X points of the Brillouin zone, while the states around the zone center Γ point are strongly renormalized. Our first-principles calculations agree with our experimental results around the X points, but not around the Γ point, indicating areas of strong renormalization located near Γ. The Ce quasi-particle states participate in the formation of hotspots at the Fermi surface, while the incoherent f states hybridize and lead to the emergence of dispersive features absent in the non-f counterpart BaB 6 . Our results provide a new understanding of the electronic structure in rare-earth hexaborides, which will be useful in elucidating the nature of the exotic low-temperature phases in these materials.

Anomaly in the temperature-dependent electronic structure of the heavy-fermion compound CeB6 : A theoretical investigation by means of a first-principles many-body approach

“…In the DMFT part, the general interaction matrix was parameterized using the Coulomb interaction U and the Hund's exchange J via the Slater integrals 42 . They were 6.0 eV and 0.7 eV, respectively, which were exactly accordance with the values reported in the literatures 34 . The fully localized limit scheme was used 43 to evaluate the double counting term.…”

“…Because of the presence of strong spin-orbit coupling, the 4 f bands are split into j = 5/2 and j = 7/2 sub-bands. The energy separation is approximately 300 meV, which is consistent with experimental observation ∆ SO =280 meV 34 . In addition, the 4 f orbitals are almost unoccupied.…”

“…The correlated electronic structure of CeB 6 is yet another important, but less concerned topic. The band structure and Fermi surface topology have been studied by using the high-resolution angle-resolved photoemission spectroscopy (ARPES) 34 . However, the temperature dependence of electronic structures of CeB 6 , especially the evolution of 4 f electronic states, is rarely considered in the available literatures.…”

Doping-induced redistribution of magnetic spectral weight in the substituted hexaborides Ce1−xLaxB6 and Nikitin1, Portnichenko2, Dukhnenko3 et al. 2018Phys. Rev. B123160View full textAdd to dashboardCite

“…On the other hand, hybridization of Ce 4 f 1 electrons with the conduction band qualitatively modifies the Fermi surface of CeB 6 as compared to LaB 6 [72]. Therefore, both La and Nd doping of CeB 6 do not simply change the number or magnitude of localized 4 f magnetic moments, but also induce an effective hole doping, decreasing the number of conduction electrons and modifying the Fermi surface geometry.…”

RKKY Interactions of CeB6 Based on Effective Wannier Model

“…The 4 f electrons of CeB 6 are almost localized from several experiments. The Fermi-surface (FS) has been observed in the de Haas-van Alphen (dHvA) experiments [3], the angle resolved photoemission spectroscopy (ARPES) [4,5] and the high-resolution photoemission tomography [6], where an ellipsoidal FS centered at X point in the Brillouin zone (BZ) has been confirmed and is almost the same as that of LaB 6 with the 4 f 0 state. In such a localized f electron system, Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction [7][8][9] plays an important role for the multipole ordering and must determine the ordering moments and wavevectors.…”