Cox Susan, Singleton J, McDonald R D, Migliori A, Littlewood P B
National High Magnetic Field Laboratory, Ms-E536, Los Alamos National Laboratory, New Mexico 87545, USA.
Nat Mater. 2008 Jan;7(1):25-30. doi: 10.1038/nmat2071. Epub 2007 Dec 2.
Stripe and chequerboard phases appear in many metal oxide compounds, and are thought to be linked to exotic behaviour such as high-temperature superconductivity and colossal magnetoresistance. It is therefore extremely important to understand the fundamental nature of such phases. The so-called stripe phase of the manganites has long been interpreted as the localization of charge at atomic sites. Here, we present resistance measurements on La(0.50)Ca(0.50)MnO(3) that strongly suggest that this state is in fact a prototypical charge-density wave (CDW) that undergoes collective transport. Dramatic resistance hysteresis effects and broadband noise properties are observed, both of which are typical of sliding CDW systems. Moreover, the high levels of disorder typical of manganites result in behaviour similar to that of well-known disordered CDW materials. The CDW-type behaviour of the manganite superstructure suggests that unusual transport and structural properties do not require exotic physics, but could emerge when a well-understood phase (the CDW) coexists with disorder.
条纹相和棋盘相出现在许多金属氧化物化合物中，并且被认为与诸如高温超导和巨磁电阻等奇异行为有关。因此，了解这些相的基本性质极其重要。长期以来，锰氧化物的所谓条纹相一直被解释为电荷在原子位点的局域化。在此，我们展示了对La(0.50)Ca(0.50)MnO(3)的电阻测量结果，这些结果强烈表明该状态实际上是一种经历集体输运的典型电荷密度波（CDW）。观察到了显著的电阻滞后效应和宽带噪声特性，这两者都是滑动CDW系统的典型特征。此外，锰氧化物典型的高度无序导致了与众所周知的无序CDW材料相似的行为。锰氧化物超结构的CDW型行为表明，不寻常的输运和结构性质并不需要奇异的物理现象，而是当一个已被充分理解的相（CDW）与无序共存时可能会出现。
