Anisimov V I, Lukoyanov A V
Institute of Metal Physics, Russian Academy of Sciences, 620990 Yekaterinburg, Russia.
Acta Crystallogr C Struct Chem. 2014 Feb;70(Pt 2):137-59. doi: 10.1107/S2053229613032312. Epub 2014 Jan 31.
Materials with strong electronic correlations are at the cutting edge of experimental and theoretical studies, capturing the attention of researchers for a great variety of interesting phenomena: metal-insulator, phase and magnetic spin transitions, `heavy fermion' systems, interplay between magnetic order and superconductivity, appearance and disappearance of local magnetic moments, and transport property anomalies. It is clear that the richness of physical phenomena for these compounds is a result of partially filled 3d, 4f or 5f electron shells with local magnetic moments preserved in the solid state. Strong interactions of d and f electrons with each other and with itinerant electronic states of the material are responsible for its anomalous properties. Electronic structure calculations for strongly correlated materials should explicitly take into account Coulombic interactions between d or f electrons. Recent advances in this field are related to the development of the LDA+DMFT method, which combines local density approximation (LDA) with dynamical mean-field theory (DMFT) to account for electronic correlation effects. In recent years, LDA+DMFT has allowed the successful treatment not only of simple systems but also of complicated real compounds. Nowadays, the LDA+DMFT method is the state-of-the-art tool for investigating correlated metals and insulators, spin and metal-insulator transitions (MIT) in transition-metal compounds in paramagnetic and magnetically ordered phases.
具有强电子关联的材料处于实验和理论研究的前沿,因其各种各样有趣的现象吸引了研究人员的关注:金属 - 绝缘体、相变和磁自旋转变、“重费米子”系统、磁有序与超导之间的相互作用、局域磁矩的出现和消失以及输运性质异常。显然,这些化合物丰富的物理现象是由于其部分填充的3d、4f或5f电子壳层以及在固态中保留的局域磁矩所致。d和f电子彼此之间以及与材料的巡游电子态的强相互作用导致了其异常性质。对于强关联材料的电子结构计算应明确考虑d或f电子之间的库仑相互作用。该领域的最新进展与LDA + DMFT方法的发展有关,该方法将局域密度近似(LDA)与动态平均场理论(DMFT)相结合以考虑电子关联效应。近年来,LDA + DMFT不仅能够成功处理简单系统,还能处理复杂的实际化合物。如今,LDA + DMFT方法是研究顺磁相和磁有序相过渡金属化合物中的关联金属和绝缘体、自旋以及金属 - 绝缘体转变(MIT)的最先进工具。