Polaron coherence condensation as the mechanism for colossal magnetoresistance in layered manganites

[摘要] Angle-resolved photoemission spectroscopy data for the bilayer manganite La1.2Sr1.8Mn2O7 show that, upon lowering the temperature below the Curie point, a coherent polaronic metallic ground state emerges very rapidly with well-defined quasiparticles which track remarkably well the electrical conductivity, consistent with macroscopic transport properties. Our data suggest that the mechanism leading to the insulator-to-metal transition in La1.2Sr1.8Mn2O7 can be regarded as a polaron coherence condensation process acting in concert with the double exchange interaction.

[发布日期] 2007-12-01

[关键词] LA1.2SR1.8MN2O7;PARTICLE;COLLAPSE;DENSITY