Gossamer metals

TL;DR

This paper extends Laughlin's gossamer state construction to normal metals, demonstrating that certain Gutzwiller wave functions are exact ground states of an extended Hubbard model, revealing correlation effects on susceptibility and a Mott transition.

Contribution

It introduces a novel application of gossamer states to normal metals, identifying exact ground states in an extended Hubbard model with correlated hopping.

Findings

Pauli susceptibility is enhanced by correlations.

Elementary quasiparticles are gapless except at g=0.

A Mott transition occurs at half-filling when g=0.

Abstract

Laughlin's construction of exact gossamer ground states is applied to normal metals. We show that for each variational parameter 0<=g<=1, the paramagnetic or ferromagnetic Gutzwiller wave function is the exact ground state of an extended Hubbard model with correlated hopping, with arbitrary particle density, non-interacting dispersion, and lattice dimensionality. The susceptibility and magnetization curves are obtained, showing that the Pauli susceptibility is enhanced by correlations. The elementary quasiparticle excitations are gapless, except for a half-filled band at g=0, where a Mott transition from metal to insulator occurs.