A representation of the 12 by 12 spectral function of the Hubbard model with variational Monte Carlo*

A method to calculate the one-body Green's function for ground states of correlated electron materials is formulated by extending the variational Monte Carlo method. The new method have been recently published in Ref. [1]. We benchmark against the exact diagonalization (ED) for the one-and two-dimensional Hubbard models of 16 site lattices, which proves high accuracy of the method. The application of the method to larger-sized Hubbard model on the square lattice correctly reproduces the Mott insulating behaviour at half-filling and gap structures of d-wave superconducting state in the hole doped Hubbard model, evidencing a wide applicability to strongly correlated electron systems.

Cherlebois M, and Imada M., Phys. Rev. X, 10:4(041023) (2020),