Microscopic Approach to Magnetism and Superconductivity of $f$-Electron Systems with Filled Skutterudite Structure

Abstract

In order to gain a deep insight into $f$-electron properties of filled skutterudite compounds from a microscopic viewpoint, we investigate the multiorbital Anderson model including Coulomb interactions, spin-orbit coupling, and crystalline electric field effect. For each case of $n$=1$\sim$13, where $n$ is the number of $f$ electrons per rare-earth ion, the model is analyzed by using the numerical renormalization group (NRG) method to evaluate magnetic susceptibility and entropy of $f$ electron. In order to make further step to construct a simplified model which can be treated even in a periodic system, we also analyze the Anderson model constructed based on the $j$-$j$ coupling scheme by using the NRG method. Then, we construct an orbital degenerate Hubbard model based on the $j$-$j$ coupling scheme to investigate the mechanism of superconductivity of filled skutterudites. In the 2-site model, we carefully evaluate the superconducting pair susceptibility for the case of $n$=2 and find that the susceptibility for off-site Cooper pair is clearly enhanced only in a transition region in which the singlet and triplet ground states are interchanged.

14 pages, 11 figures, Typeset with jpsj2.cls

References in corpus (4)

• Quadrupolar effect and rattling motion in heavy fermion superconductor PrOs_4Sb_{12}
• Orbital-based Scenario for Magnetic Structure of Neptunium Compounds
• Exciton Mediated Superconductivity in PrOs4Sb12
• Magnetic Fluctuations of Filled Skutterudites Emerging in the Transition Region between Singlet and Triplet States

Cited by in corpus (15)

• Orbital ordering phenomena in $d$- and $f$-electron systems
• Quasi-Kondo Phenomenon due to Dynamical Jahn-Teller Effect
• Analysis of f-p model for octupole ordering in NpO2
• Effective Crystalline Electric Field Potential in a j-j Coupling Scheme
• Multipole ordering in f-electron systems on the basis of a j-j coupling scheme
• Effect of Spin-Orbit Coupling on Kondo Phenomena in $f^7$-Electron Systems
• Multipole Susceptibility of Multiorbital Anderson Model Coupled with Jahn-Teller Phonons
• Multipole State of Heavy Lanthanide Filled Skutterudites
• Exciton Mediated Triplet Superconductivity in Th System PrOs4Sb12
• Magnetic behavior of curium dioxide with non-magnetic ground state
• Microscopic Aspects of Multipole Properties of Filled Skutterudites
• Multipole as $f$-Electron Spin-Charge Density in Filled Skutterudites
• Multipole Fluctuations in Filled Skutterudites
• Multipole correlations in low-dimensional f-electron systems
• Quadrupole Susceptibility of Gd-Based Filled Skutterudite Compounds