Thermodynamic Evidence of Proximity to a Kitaev Spin-Liquid in Ag${}_3$LiIr${}_2$O${}_6$

Abstract

Kitaev magnets are materials with bond-dependent Ising interactions between localized spins on a honeycomb lattice. Such interactions could lead to a quantum spin-liquid (QSL) ground state at zero temperature. Recent theoretical studies suggest two potential signatures of a QSL at finite temperatures, namely a scaling behavior of thermodynamic quantities in the presence of quenched disorder, and a two-step release of the magnetic entropy. Here, we present both signatures in Ag${}_3$LiIr${}_2$O${}_6$ which is synthesized from $\alpha$-Li${}_2$IrO${}_3$ by replacing the inter-layer Li atoms with Ag atoms. In addition, the DC susceptibility data confirm absence of a long-range order, and the AC susceptibility data rule out a spin-glass transition. These observations suggest a closer proximity to the QSL in Ag${}_3$LiIr${}_2$O${}_6$ compared to its parent compound $\alpha$-Li${}_2$IrO${}_3$ that orders at 15 K. We discuss an enhanced spin-orbit coupling due to a mixing between silver d and oxygen p orbitals as a potential underlying mechanism.

6 pages, 4 figures, 2 tables

References in corpus (4)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Importance of anisotropic exchange interactions in honeycomb iridates. Minimal model for zigzag antiferromagnetic order in Na${}_2$IrO${}_3$
• Analysis of the optical conductivity for A2IrO3 (A = Na, Li) from first principles

Cited by in corpus (1)

• Accessing new magnetic regimes by tuning the ligand spin-orbit coupling in van der Waals magnets