Open AccessLocalization of electrons due to orbitally ordered bi-stripes in the bilayer manganite La 2-2 x Sr 1+2 x Mn 2 O 7 ( x ∼ 0.59)
Author(s) -
Zhe Sun,
Q. Wang,
A. V. Fedorov,
Hong Zheng,
J. F. Mitchell,
D. S. Dessau
Publication year - 2011
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.1018604108
Subject(s) - condensed matter physics , electron , manganite , scattering , materials science , physics , optics , ferromagnetism , quantum mechanics
Electronic phases with stripe patterns have been intensively investigated for their vital roles in unique properties of correlated electronic materials. How these real-space patterns affect the conductivity and other properties of materials (which are usually described in momentum space) is one of the major challenges of modern condensed matter physics. By studying the electronic structure of La2-2x Sr1+2x Mn2 O7 (x ∼ 0.59) and in combination with earlier scattering measurements, we demonstrate the variation of electronic properties accompanying the melting of so-called bi-stripes in this material. The static bi-stripes can strongly localize the electrons in the insulating phase aboveT c ∼ 160 K, while the fraction of mobile electrons grows, coexisting with a significant portion of localized electrons when the static bi-stripes melt belowT c . The presence of localized electrons belowT c suggests that the melting bi-stripes exist as a disordered or fluctuating counterpart. From static to melting, the bi-stripes act as an atomic-scale electronic valve, leading to a “colossal” metal-insulator transition in this material.