A local metallic state in globally insulating $La_{1.24}Sr_{1.76}Mn_2O_7$ well above the metal-insulator transition

Z. Sun; J. F. Douglas; A. V. Fedorov; Y. -D. Chuang; H. Zheng; J. F. Mitchell; D. S. Dessau

doi:10.1038/nphys517

paper

A local metallic state in globally insulating $L a_{1.24} S r_{1.76} M n_{2} O_{7}$ well above the metal-insulator transition

arXiv:cond-mat/0611074 · doi:10.1038/nphys517

Abstract

Angle-resolved photoemission spectroscopy was used to investigate the evolution of the electronic structure across the metal-insulator transition in bi-layer manganite $L a_{1.24} S r_{1.76} M n_{2} O_{7}$ . We found that this system is a metal for $T < T_{C}$ , a local metal but global insulator for $T < T_{C} < T^{*}$ , and a global insulator for $T > T^{*}$ . These results indicate the critical role of electronic phase separation and percolation effects for the metal-insulator transition in $L a_{1.24} S r_{1.76} M n_{2} O_{7}$ .

4 pages, 4 figures

A local metallic state in globally insulating La1.24​Sr1.76​Mn2​O7​ well above the metal-insulator transition

Abstract

A local metallic state in globally insulating $L a_{1.24} S r_{1.76} M n_{2} O_{7}$ well above the metal-insulator transition