Kitaev Spin Liquid in 3d Transition Metal Compounds.

Huimei Liu,Giniyat Khaliullin,Jiří Chaloupka

doi:10.1103/physrevlett.125.047201

Abstract

We study the exchange interactions and resulting magnetic phases in the honeycomb cobaltates. For a broad range of trigonal crystal fields acting on Co^{2+} ions, the low-energy pseudospin-1/2 Hamiltonian is dominated by bond-dependent Ising couplings that constitute the Kitaev model. The non-Kitaev terms nearly vanish at small values of trigonal field Δ, resulting in spin liquid ground state. Considering Na_{3}Co_{2}SbO_{6} as an example, we find that this compound is proximate to a Kitaev spin liquid phase, and can be driven into it by slightly reducing Δ by ∼20 meV, e.g., via strain or pressure control. We argue that, due to the more localized nature of the magnetic electrons in 3d compounds, cobaltates offer the most promising search area for Kitaev model physics.

Highlights

The Kitaev honeycomb model [1], demonstrating the key concepts of quantum spin liquids [2] via an elegant exact solution, has attracted much attention
For a broad range of trigonal crystal fields acting on Co2þ ions, the low-energy pseudospin-1=2 Hamiltonian is dominated by bond-dependent Ising couplings that constitute the Kitaev model
Considering Na3Co2SbO6 as an example, we find that this compound is proximate to a Kitaev spin liquid phase, and can be driven into it by slightly reducing Δ by ∼20 meV, e.g., via strain or pressure control

Summary

Introduction

The Kitaev honeycomb model [1], demonstrating the key concepts of quantum spin liquids [2] via an elegant exact solution, has attracted much attention (see the recent reviews [3,4,5,6,7]). We study the exchange interactions and resulting magnetic phases in the honeycomb cobaltates. For a broad range of trigonal crystal fields acting on Co2þ ions, the low-energy pseudospin-1=2 Hamiltonian is dominated by bond-dependent Ising couplings that constitute the Kitaev model.

Objectives

Results

Conclusion