Gutzwiller wave function under magnetic field

TL;DR

This paper investigates the magnetization process of the Gutzwiller wave function in various models using variational Monte Carlo, revealing discontinuous magnetization in the Hubbard model and ferromagnetic instability in the periodic Anderson model.

Contribution

It provides accurate variational Monte Carlo analysis of the Gutzwiller wave function under magnetic fields for multiple models, including 1D and 2D Hubbard models and the 1D periodic Anderson model.

Findings

Discontinuous magnetization to full moment in 1D and 2D Hubbard models.

Paramagnetic state in PAM is unstable against ferromagnetism.

Small energy reduction favors ferromagnetic ordering in PAM.

Abstract

Magnetization process of the Gutzwiller wave function is studied accurately by a variational Monte Carlo method. We apply it to the one-dimensional (1D) and 2D Hubbard models (HM), and to the 1D periodic Anderson model (PAM) without orbital degeneracy. For the HM, magnetization varies discontinuously to the full moment, as the magnetic field increases. For the PAM, the paramagnetic state is unstable against ferromagnetism, although the energy reduction thereof is small.