论文标题
在波函数和密度功能理论中的地面对称性断裂和强相关性的解释
Interpretations of ground-state symmetry breaking and strong correlation in wavefunction and density functional theories
论文作者
论文摘要
对称不封闭的地面波函数内的强相关性可以以近似密度的功能理论显示为对称性旋转的自旋态或总密度，有时可以观察到。它们可能是由柔软的波动模式（有时是集体激发）引起的，例如在非零波形处的旋转密度或电荷密度波。从这个意义上讲，与不相比，打破对称性的交换和相关性的近似密度可以比没有的确切功能更易于揭示（尽管准确）。此处讨论的示例包括伸展的H $ _2 $分子，抗磁磁固体以及低密度jellium的静态电荷密度波/Wigner晶体相。结果表明，（在什么意义上）静态电荷密度波是软等离子体。
Strong correlations within a symmetry-unbroken ground-state wavefunction can show up in approximate density functional theory as symmetry-broken spin-densities or total densities, which are sometimes observable. They can arise from soft modes of fluctuations (sometimes collective excitations) such as spin-density or charge-density waves at non-zero wavevector. In this sense, an approximate density functional for exchange and correlation that breaks symmetry can be more revealing (albeit less accurate) than an exact functional that does not. The examples discussed here include the stretched H$_2$ molecule, antiferromagnetic solids, and the static charge-density wave/Wigner crystal phase of a low-density jellium. It is shown that (and in what sense) the static charge density wave is a soft plasmon.
