$\mathrm{SU}(4)$-Symmetric Quantum Spin-Orbital Liquids on Various Lattices

TL;DR

This paper explores the emergence of $ ext{SU}(4)$ symmetric quantum spin-orbital liquids in various lattice structures, highlighting their fractionalized excitations and potential for exotic ground states due to multicomponent frustration.

Contribution

It introduces models of $ ext{SU}(4)$ symmetric quantum spin-orbital liquids on different lattices, emphasizing their fractionalization and potential for hosting novel excitations.

Findings

Potential for quantum spin-orbital liquid ground states in $ ext{SU}(4)$ models.

Existence of fractionalized excitations including spinons and orbitalons.

Relevance to $d^1$ honeycomb materials with multicomponent frustration.

Abstract

An emergent $\mathrm{SU}(4)$ symmetry discovered in the microscopic model for $d^1$ honeycomb materials [M.~G.~Yamada, M.~Oshikawa, and G.~Jackeli, Phys. Rev. Lett. \textbf{121}, 097201 (2018).] has enabled us to tailor exotic $\mathrm{SU}(4)$ models in real materials. In the honeycomb structure, the emergent $\mathrm{SU}(4)$ Heisenberg model would potentially have a quantum spin-orbital liquid ground state due to the \textit{multicomponent frustration}, and we can expect similar spin-orbital liquids also in three-dimensinal versions of the honeycomb lattice. In such quantum spin-orbital liquids, both the spin and orbital degrees of freedom become fractionalized and entangled together due to the strong frustrated interactions between them. Similarly to spinons in pure quantum spin liquids, quantum spin-orbital liquids can host not only spinon excitations, but also fermionic \textit{orbitalon} excitations at low temperature.