Quantum Phase Transition in the SU(4) Spin-Orbital Model on the Triangular Lattice

TL;DR

This paper investigates a quantum phase transition in an SU(4) spin-orbital model on a triangular lattice, revealing a transition to a stable liquid phase with suppressed long-range correlations, relevant to layered oxides like LiNiO2 and BaVS3.

Contribution

It demonstrates a quantum phase transition driven by next-nearest neighbour coupling and characterizes the resulting liquid phase as stable and lacking long-range order.

Findings

Transition to a liquid phase upon reducing next-nearest neighbour coupling

Liquid phase exhibits suppressed long-range correlations

Phase transition is relevant to layered oxides without Jahn-Teller effect

Abstract

Motivated by the absence of cooperative Jahn-Teller effect in LiNiO2 and BaVS3, two layered oxides with triangular planes, we study the SU(4) symmetric spin-orbital model on the triangular lattice. Upon reducing the next-nearest neighbour coupling, we show that the system undergoes a quantum phase transition to a liquid phase. A variational approach to this liquid phase shows that simple types of long-range correlations are suppressed, suggesting that it is stable against lattice distortions.