Phase separation and stripe formation in the 2D t-J model: a comparison of numerical results

TL;DR

This paper critically analyzes numerical results for the 2D t-J model, concluding that the ground state is striped rather than phase separated, based on the most accurate density matrix renormalization group calculations.

Contribution

It provides a comparative analysis of numerical methods and clarifies the nature of the ground state in the doped t-J model, emphasizing the role of stripe formation.

Findings

Density matrix renormalization group yields the most accurate energies for large systems.

Ground state of the doped t-J model is striped, not phase separated.

Frustrated phase separation mechanism is inconsistent with numerical results.

Abstract

We make a critical analysis of numerical results for and against phase separation and stripe formation in the t-J model. We argue that the frustrated phase separation mechanism for stripe formation requires phase separation at too high a doping for it to be consistent with existing numerical studies of the t-J model. We compare variational energies for various methods, and conclude that the most accurate calculations for large systems appear to be from the density matrix renormalization group. These calculations imply that the ground state of the doped t-J model is striped, not phase separated.