Existence of an incommensurate ground state of interacting spinless fermions in infinite dimensions

TL;DR

This paper investigates the ground state phases of interacting spinless fermions in infinite dimensions, revealing a charge density wave phase and exploring incommensurate states using a novel ansatz.

Contribution

It introduces a new ansatz for the order parameter that captures homogeneous, AB, and incommensurate phases, enabling detailed phase diagram calculations.

Findings

Identification of a charge density wave in the ground state

Existence of incommensurate phases in the phase diagram

Comprehensive phase diagram including various symmetry-breaking states

Abstract

We focus on the ground state phase diagram of a system of spinless fermions with repulsion on a hypercubic lattice in the limit of infinite dimensions. It occurs spontaneous symmetry breaking into a charge density wave (CDW). Using an ansatz for the order parameter which includes the homogeneous, the AB- and a large class of incommensurate phases we are able to calculate the phase diagram.