Stabilizing the spiral order with spin-orbit coupling in an anisotropic triangular antiferromagnet

TL;DR

This paper investigates how spin-orbit coupling influences the magnetic order in an anisotropic triangular antiferromagnet, revealing that SOC stabilizes spiral magnetic order and alters spin correlations.

Contribution

It demonstrates that spin-orbit coupling stabilizes spiral order in the anisotropic triangular antiferromagnet and affects the spin correlations and phase boundary.

Findings

SOC induces zero-temperature Schwinger boson condensation with a single momentum

Spin correlations vanish along the z-axis but develop in the x-y plane

SOC extends the phase boundary, stabilizing spiral magnetic order

Abstract

We study the effects of spin-orbit coupling (SOC) on the large-U Hubbard model on anisotropic triangular lattice at half-filling using the Schwinger-boson method. We find that the SOC will in general lead to a zero temperature condensation of the Schwinger bosons with a single condensation momentum. As a consequence, the spin-spin correlation vanishes along the z-axis but develops in the $x$-$y$ plane, with the ordering wave vector being dramatically dependent on the SOC. Moreover, the phase boundary of the magnetic ordered state extends to the region of large spatial anisotropy with increased condensation density, demonstrating that the spiral order is always stabilized by the SOC.