Dagotto Elbio
Department of Physics, University of Tennessee (UT), Knoxville, TN 37996-1200, USA. Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6393, USA.
Science. 2005 Jul 8;309(5732):257-62. doi: 10.1126/science.1107559.
A wide variety of experimental results and theoretical investigations in recent years have convincingly demonstrated that several transition metal oxides and other materials have dominant states that are not spatially homogeneous. This occurs in cases in which several physical interactions-spin, charge, lattice, and/or orbital-are simultaneously active. This phenomenon causes interesting effects, such as colossal magnetoresistance, and it also appears crucial to understand the high-temperature superconductors. The spontaneous emergence of electronic nanometer-scale structures in transition metal oxides, and the existence of many competing states, are properties often associated with complex matter where nonlinearities dominate, such as soft materials and biological systems. This electronic complexity could have potential consequences for applications of correlated electronic materials, because not only charge (semiconducting electronic), or charge and spin (spintronics) are of relevance, but in addition the lattice and orbital degrees of freedom are active, leading to giant responses to small perturbations. Moreover, several metallic and insulating phases compete, increasing the potential for novel behavior.
近年来，各种各样的实验结果和理论研究令人信服地表明，几种过渡金属氧化物和其他材料具有非空间均匀的主导态。这种情况发生在几种物理相互作用——自旋、电荷、晶格和/或轨道——同时起作用的情形中。这种现象会导致诸如巨磁电阻等有趣的效应，并且对于理解高温超导体似乎也至关重要。过渡金属氧化物中电子纳米尺度结构的自发出现以及许多竞争态的存在，是通常与非线性占主导的复杂物质相关的性质，例如软材料和生物系统。这种电子复杂性可能会对关联电子材料的应用产生潜在影响，因为不仅电荷（半导体电子）或电荷与自旋（自旋电子学）与之相关，而且晶格和轨道自由度也起作用，导致对小扰动产生巨大响应。此外几种金属相和绝缘相相互竞争，增加了出现新行为的可能性。
