1510.05634v1.pdf

We study the best Slater approximation of an N-fermion wave function analytically. That is, we seek the Slater determinant (constructed out of Northonormal single-particle orbitals) wave function having largest overlap with a given N-fermion wave function. Some simple lemmas have been established and their usefulness is demonstrated on some structured states, such as the GHZ state. In the simplest nontrivial case of three fermions in six orbitals, which the celebrated Borland-Dennis discovery is about, the best Slater approximation wave function is proven to be built out of the natural orbitals in an interesting way. We also show that the Hadamard inequality is useful for finding the best Slater approximation of some special target wave functions.

这个文章是我们之前工作Optimal multiconfiguration approximation of an N-fermion wave function

PhysRevA.89.012504.pdf

的继续。

Geometric measure of entanglement通常比较难计算。不过，在某些特殊的情况下，还是可以解析算的。

欢迎无保留地提意见！谢谢！