Magnetic phases of the anisotropic triangular lattice Hubbard model

TL;DR

This paper explores the complex magnetic phases of the anisotropic triangular lattice Hubbard model using a dual fermion approach, revealing various magnetic orders and comparing results with previous studies.

Contribution

It applies the ladder dual fermion approximation to analyze the phase diagram, capturing local correlations and identifying multiple magnetic phases in the model.

Findings

Identifies metallic, antiferromagnetic, and spiral phases.

No evidence of collinear antiferromagnetic order.

Discusses agreement and discrepancies with previous work.

Abstract

The Hubbard model on an anisotropic triangular lattice in two dimensions, a fundamental model for frustrated electron physics, displays a wide variety of phases and phase transitions. This work investigates the model using the ladder dual fermion approximation which captures local correlations non-perturbatively but approximates non-local correlations. We find metallic, one-dimensional antiferromagnetic, non-collinear antiferromagnetic, square-lattice antiferromagnetic, and spiral phases but no evidence of collinear antiferromagnetic order in different parts of the phase diagram. Analyzing the spin susceptibility in detail, we see both regions of agreement and of discrepancy with previous work. The case of Cs$_2$CuCl$_4$ is discussed in detail.