Dimensional tuning of electronic states under strong and frustrated interactions

TL;DR

This paper investigates how strong interactions and lattice anisotropy influence electronic states in a model of spinless fermions, revealing a tunable dimensional behavior and potential experimental signatures of charge excitations.

Contribution

It introduces an effective model describing low-energy excitations and analyzes the stability of the phase with fractionalized and free particle propagation.

Findings

Fermions form stripe-ordered insulating states at strong interactions.

Doped particles exhibit either 1D free motion or fractionalization perpendicular to stripes.

Spectral functions suggest experimental detection of charge excitations.

Abstract

We study a model of strongly interacting spinless fermions on an anisotropic triangular lattice. At half-filling and the limit of strong repulsive nearest-neighbor interactions, the fermions align in stripes and form an insulating state. When a particle is doped, it either follows a one-dimensional free motion along the stripes or fractionalizes perpendicular to the stripes. The two propagations yield a dimensional tuning of the electronic state. We study the stability of this phase and derive an effective model to describe the low-energy excitations. Spectral functions are presented which can be used to experimentally detect signatures of the charge excitations.