Produção Nacional
Frustration in the Kondo lattice model: Local versus extended singlet phases
2011; American Physical Society; Volume: 83; Issue: 21 Linguagem: Inglês
10.1103/physrevb.83.214427
ISSN1550-235X
AutoresB.H. Bernhard, B. Coqblin, C. Lacroix,
Tópico(s)Iron-based superconductors research
ResumoWe present a theoretical study of the frustrated Kondo lattice model on a Shastry-Sutherland-type lattice. Using a mean-field decoupling on both the Kondo and intersite exchange interactions, we study three different phases, an antiferromagnetic (AF) phase without Kondo effect, a Kondo (K) phase without magnetic order, and finally a valence bond solid (VBS) phase without magnetic order and Kondo effect. A phase diagram is obtained giving the stability region of the three phases, as a function of the Kondo parameter ${J}_{K}$ and the frustration ratio $J/{J}^{\ensuremath{'}}$ of the two exchange interactions on the Shastry-Sutherland lattice. This phase diagram can account for the change under pressure from a nonmagnetic Kondo phase to an AF phase and to a completely different nonmagnetic VBS phase occurring in some ytterbium compounds such as Yb${}_{2}$Pd${}_{2}$Sn.
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