论文标题
将Gutzwiller近似扩展到相互作用
Extending the Gutzwiller approximation to intersite interactions
论文作者
论文摘要
我们开发了Gutzwiller近似（GA）形式主义的扩展，其中包括任意范围的库仑相互作用（包括密度密度，交换，配对和库仑辅助跳跃术语）。这种形式主义仅在仅存在局部相互作用的情况下，将多种频带哈伯德模型的普通GA形式主义减少了。这是通过将1/z扩展的结合（z是协调数，只有领先顺序术语在无限维度极限的情况下）与p^2-1扩展，其中P是Gutzwiller投影仪。该方法是根据Gutzwiller Lagrange功能方便地制定的。我们将理论应用于扩展的单个频段哈伯德模型。与通常的Brinkman-Rice机制类似，我们发现了Mott的过渡。观察到了价跳过的转变，其中相对于不相关的Slater决定因素波函数增强了空的和双重占用状态的Gutzwiller波函数。
We develop an extension of the Gutzwiller Approximation (GA) formalism that includes the effects of Coulomb interactions of arbitrary range (including density density, exchange, pair hopping and Coulomb assisted hopping terms). This formalism reduces to the ordinary GA formalism for the multi-band Hubbard models in the presence of only local interactions. This is accomplished by combining the 1/z expansion -- where z is the coordination number and only the leading order terms contribute in the limit of infinite dimensions -- with a P^2-I expansion, where P is the Gutzwiller projector. The method is conveniently formulated in terms of a Gutzwiller Lagrange function. We apply our theory to the extended single band Hubbard model. Similarly to the usual Brinkman-Rice mechanism we find a Mott transition. A valence skipping transition is observed, where the occupation of the empty and doubly occupied states for the Gutzwiller wavefunction is enhanced with respect to the uncorrelated Slater determinant wavefunction.
