A possible phase diagram of a t-J ladder model

TL;DR

This paper explores the phase diagram of a t-J ladder model using numerical methods, revealing potential superconducting regions dependent on J/t ratios and electron density, consistent with Luttinger liquid theory.

Contribution

It provides a numerical phase diagram of the t-J ladder model and links correlation functions to Luttinger liquid predictions, highlighting conditions for superconductivity.

Findings

Superconducting phase appears at J/t > 0.5 for high density

Superconducting phase appears at J/t > 2.0 for low density

Correlation functions align with Luttinger liquid theory predictions

Abstract

We investigate a t-J ladder model by numerical diagonalization method. By calculating correlation functions and assuming the Luttinger liquid relation, we obtained a possible phase diagram of the ground state as a function of J/t and electron density $n$. We also found that behavior of correlation functions seems to consist with the prediction of Luttinger liquid relation. The result suggests that the superconducting phase appear in the region of $J/t \displaystyle{ \mathop{>}_{\sim}} 0.5$ for high electron density and $J/t \displaystyle{ \mathop{>}_{\sim}} 2.0$ for low electron density.