Failure of Gutzwiller-type wave function to capture gauge fluctuations: Case study in the Exciton Bose Liquid context

TL;DR

This paper demonstrates that Gutzwiller wave functions fail to accurately describe the long-wavelength physics of the Exciton Bose Liquid phase due to neglecting dynamical gauge field fluctuations, highlighting limitations of simplified slave particle approaches.

Contribution

The study compares Gutzwiller wave functions with accurate EBL wave functions and shows the importance of dynamical gauge fluctuations for correct long-wavelength descriptions.

Findings

Gutzwiller projection alone misses key gauge fluctuation effects.

Dynamical gauge fields are essential for accurate EBL modeling.

Gutzwiller wave functions may not capture long-wavelength physics.

Abstract

Slave particle approaches are widely used in studies of exotic quantum phases. A complete description beyond mean field also contains dynamical gauge fields, while a simplified procedure considers Gutzwiller-projected trial states. We apply this in the context of bosonic models with ring exchanges realizing so-called Exciton Bose Liquid (EBL) phase and compare a Gutzwiller wave function against an accurate EBL wave function. We solve the parton-gauge theory and show that dynamical fluctuations of the spatial gauge fields are necessary for obtaining qualitatively accurate EBL description. On the contrary, just the Gutzwiller projection leads to a state with subtle differences in the long-wavelength properties, thus suggesting that Gutzwiller wave functions may generally fail to capture long-wavelength physics.