Phase Competition in the Double-Exchange Model on the Frustrated Pyrochlore Lattice

Yukitoshi Motome, Nobuo Furukawa
2010 Physical Review Letters  
Competition between the ferromagnetic double-exchange interaction and the super-exchange antiferromagnetic interaction is theoretically studied in the presence of geometrical frustration. As increasing the super-exchange interaction, the ferromagnetic metal becomes unstable, and is taken over by a cooperative paramagnetic metal, in sharp contrast with a discontinuous transition to the antiferromagnetic insulator in the absence of frustration. In the critical region, the system exhibits a
more » ... r temperature-independent behavior with highly incoherent transport, suggesting a large residual entropy at low temperatures. We discuss the relevance of the results to the pressure-induced behaviors in Mo pyrochlore oxides [S. Iguchi et al., Phys. Rev. Lett. 102, 136407 (2009)].
doi:10.1103/physrevlett.104.106407 pmid:20366445 fatcat:hmyaikzalbas5j4elnwq4tsrvm