Triplet superconductivity vs. easy-plane ferromagnetism in a 1D itinerant electron system with transverse spin anisotropy

TL;DR

This paper investigates the phase diagram of a 1D $t-U-J$ model at half-filling, revealing a coexistence of triplet superconductivity and spin density wave instabilities in the large-bandwidth limit, and a transition to an insulating phase as bandwidth decreases.

Contribution

It provides a detailed analysis of the ground state phases of a 1D itinerant electron system with transverse spin anisotropy, highlighting the coexistence of superconductivity and magnetic order.

Findings

Coexistence of triplet superconductivity and spin density wave in the large-bandwidth limit.

Transition to an insulating phase with XY model properties as bandwidth decreases.

Identification of phase boundaries in the $t-U-J$ model at half-filling.

Abstract

In this paper we study the ground state phase diagram of a one-dimensional $t-U-J$ model, at half-filling. In the large-bandwidth limit and for ferromagnetic exchange with easy-plane anisotropy, a phase with gapless charge and massive spin excitations, characterized by the coexistence of triplet superconducting and spin density wave instabilities is realized in the ground state. With reduction of the bandwidth, a transition into an insulating phase showing properties of the spin-1/2 XY model takes place.