An analysis of the $t_2-V$ model

TL;DR

This paper investigates the one-dimensional $t_2-V$ model, revealing a discontinuous superfluid to supersolid transition influenced by topological differences, and connects it to other topological models using analytic and numerical methods.

Contribution

It provides the first detailed analysis of the $t_2-V$ model, highlighting its phase transition behavior and topological distinctions, with implications for electron-phonon systems.

Findings

Discontinuous superfluid to supersolid transition observed

Topological differences manifest in structure factor peaks

Connections established with other topologically interesting models

Abstract

We study a model (i.e., the $t_2-V$ model involving {\em next-nearest-neighbor hopping} and nearest-neighbor repulsion) in one-dimension that generically depicts the dominant transport mechanism in cooperative strong electron-phonon interaction systems. Using analytic and numerical approaches, hard-core-bosons are shown to typically undergo a striking discontinuous transition from a superfluid to a supersolid. Topological inequivalence of rings with even and odd number of sites is manifested through observable differences (in structure factor peaks) at the transition. Connections are also identified between the $t_2-V$ model and other topologically interesting models.