Albers R C, Christensen N E, Svane A
Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
J Phys Condens Matter. 2009 Aug 26;21(34):343201. doi: 10.1088/0953-8984/21/34/343201. Epub 2009 Aug 5.
The last decade has seen a large increase in the number of electronic-structure calculations that involve adding a Hubbard term to the local-density approximation band-structure Hamiltonian. The Hubbard term is then determined either at the mean-field level or with sophisticated many-body techniques such as using dynamical mean-field theory. We review the physics underlying these approaches and discuss their strengths and weaknesses in terms of the larger issues of electronic structure that they involve. In particular, we argue that the common assumptions made to justify such calculations are inconsistent with what the calculations actually do. Although many of these calculations are often treated as essentially first-principles calculations, in fact, we argue that they should be viewed from an entirely different point of view, namely, as based on phenomenological many-body corrections to band-structure theory. Alternatively, it may also be considered that they are just based on a Hubbard model that is more complex than the simple one- or few-band models traditionally used in many-body theories of solids.
在过去十年中，涉及在局域密度近似能带结构哈密顿量中加入哈伯德项的电子结构计算数量大幅增加。然后，哈伯德项要么在平均场水平上确定，要么使用诸如动态平均场理论等复杂的多体技术来确定。我们回顾这些方法背后的物理原理，并根据它们所涉及的电子结构的更大问题讨论其优缺点。特别是，我们认为为证明此类计算合理而做出的常见假设与计算实际所做的事情不一致。尽管许多此类计算通常被视为本质上的第一性原理计算，但事实上，我们认为应该从一个完全不同的角度来看待它们，即基于对能带结构理论的唯象多体修正。或者，也可以认为它们仅仅基于一个比传统固体多体理论中使用的简单单带或少数能带模型更复杂的哈伯德模型。
