2009/01/26 by Gertrud Zwicknagl, G. Zwicknagl, Peter Thalmeier +3
Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Atomic physics #Chemistry #Condensed matter physics #Crystallography #Effective mass (spring–mass system) #Field (mathematics) #Magnetic and transport properties of perovskites and related materials #Physics #Quantum mechanics #Quasiparticle #Rare-earth and actinide compounds #Scattering #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.79.115132
published as Phys. Rev.B 79, 115132 (2009) · 12 pages, 5 figures
arxiv created 2009/01/26 · openalex publication_date 2009/03/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The scattering of conduction electrons by crystalline electric field (CEF) excitations may enhance their effective quasiparticle mass similar to scattering from phonons. A well-known example is Pr metal where the isotropic exchange scattering from inelastic singlet-singlet excitations causes the mass enhancement. An analogous mechanism may be at work in the skutterudite compounds Pr_1\ensuremath-xLaxOs4Sb12 where close to x=1 the compound develops heavy quasiparticles with a large specific heat \ensuremathγ. There the low-lying CEF states are a singlet ground state and a triplet at \ensuremathΔ=8 K. Due to the tetrahedral CEF the main scattering mechanism must be the aspherical Coulomb scattering. We derive the expression for mass enhancement in this model including also the case of dispersive excitations. We show that for small to moderate dispersion there is a strongly field-dependent mass enhancement due to the field-induced triplet splitting. It is suggested that this effect may be seen in Pr_1\ensuremath-xLaxOs4Sb12 with suitably large x when the dispersion is small.