Triplet superconductivity in a 1D itinerant electron system with transverse spin anisotropy

TL;DR

This paper investigates the phase diagram of a 1D t-J-U model, revealing a triplet superconducting phase with gapless charge and massive spin excitations, influenced by ferromagnetic exchange and spin anisotropy.

Contribution

It introduces a detailed analysis of triplet superconductivity in a 1D itinerant electron system with transverse spin anisotropy, highlighting phase transitions driven by ferromagnetic exchange.

Findings

Existence of a triplet superconducting phase with gapless charge and massive spin excitations.

Transition to ferrometallic and spin gapped triplet superconducting phases with increasing ferromagnetic exchange.

Coexistence of triplet superconductivity and spin density wave instabilities in the ground state.

Abstract

In this paper we study the ground state phase diagram of a one-dimensional t-J-U model away from 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 increasing ferromagnetic exchange transitions into a ferrometallic and then a spin gapped triplet superconducting phase take place.