Disorder in the 1D spinless Holstein model

TL;DR

This paper studies a one-dimensional spinless fermion system coupled with quantized phonons, revealing a disordered ground state at weak coupling, contrasting with the ordered state in the static phonon case.

Contribution

It demonstrates that quantum phonon effects induce disorder in the ground state of the 1D Holstein model at weak coupling, unlike the static phonon scenario.

Findings

Disordered ground state at small coupling for any density

Contrasts with ordered ground state in static Holstein model at half filling

Quantum phonons induce disorder not present in classical phonon models

Abstract

We investigate a spinless fermion system on a one dimensional lattice interacting locally with the optical modes of a quantized phonon field: the Holstein model. The system is shown to have a disordered ground state, for small enough coupling, at any density. This is in contrast to the non quantized phonon case, the static Holstein model, which at half filling has an ordered ground state for all couplings.