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arXiv · 2402.08083

Continuum of magnetic excitations in the Kitaev honeycomb iridate D$_3$LiIr$_2$O$_6$

Thomas Halloran·Yishu Wang·K. W. Plumb·M. B. Stone·Barry Winn·M. K. Graves-Brook·J. A. Rodriguez-Rivera·Yiming Qui·Prashant Chauhan·Johannes Knolle·Roderich Moessner·N. P. Armitage·Tomohiro Takayama·Hidenori Takagi·Collin Broholm
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Abstract

Inelastic neutron scattering (INS) measurements of powder D$_3(^{7}$Li)($^{193}$Ir)$_2$O$_6$ reveal low energy magnetic excitations with a scattering cross section that is broad in $|Q|$ and consistent with a Kitaev spin-liquid (KSL) state. The magnetic nature of the excitation spectrum is demonstrated by longitudinally polarized neutron studies. The total magnetic moment of 1.7(2)$\mu_B$/Ir inferred from the total magnetic scattering cross section is consistent with the effective moment inferred from magnetic susceptibility data and expectations for the $J_{\rm eff}=1/2$ single ion state. The rise in the dynamic correlation function ${\cal S}(Q,\omega)$ for $\hbar\omega<5~$meV can be described by a nearest-neighbor Kitaev model with interaction strength $K\approx-13(5)$~meV. Exchange disorder associated with the mixed D-Li site could play an important role in stabilizing the low $T$ quantum fluctuating state.

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Thomas Halloran, Yishu Wang, K. W. Plumb, M. B. Stone, Barry Winn, M. K. Graves-Brook, J. A. Rodriguez-Rivera, Yiming Qui, Prashant Chauhan, Johannes Knolle, Roderich Moessner, N. P. Armitage, Tomohiro Takayama, Hidenori Takagi, Collin Broholm. 2024-02-12. Continuum of magnetic excitations in the Kitaev honeycomb iridate D$_3$LiIr$_2$O$_6$. https://arxiv.org/abs/2402.08083

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