Pseudospin heat conductivity in the $J_{\mathrm{eff}}=1/2$ antiferromagnet Sr${}_2$IrO${}_4$

Abstract

We report the in-plane and out-of-plane heat conductivity of the antiferromagnetic spin-orbit induced Mott insulator Sr${}_2$IrO${}_4$ with $J_{\mathrm{eff}}=1/2$. Our data reveal clear-cut evidence for magnetic heat transport within the IrO${}_2$ planes which provides the unique possibility to analyze the thermal occupation and scattering of $J_{\mathrm{eff}}=1/2$ pseudospin excitations. The analysis of the magnetic heat conductivity yields a low-temperature ($T\lesssim 75$ K) magnetic mean free path $l_{\mathrm{mag}}\sim 32$ nm, consistent with boundary scattering. Upon heating towards room temperature, the mean free path strongly decreases by one order of magnitude due to thermally activated scattering of the pseudospin excitations. The latter reveals that the coupling of these excitations to the lattice is radically different from that of $S=1/2$-excitations in cuprate analogs.

References in corpus (9)

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Cited by in corpus (9)

• Anomalous thermal conductivity and magnetic torque response in the honeycomb magnet $\alpha$-RuCl${}_3$
• Large field-induced gap of Kitaev-Heisenberg paramagnons in $\alpha$-RuCl${}_3$
• The Challenge of Spin-Orbit-Tuned Ground States in Iridates
• Heat transport of cuprate-based low-dimensional quantum magnets with strong exchange coupling
• Raman scattering study of vibrational and magnetic excitations in Sr${}_{2-x}$La${}_x$IrO${}_4$
• Quantum liquid from strange frustration in the trimer magnet Ba4Ir3O10
• Impurity-induced phonon thermal Hall effect in the antiferromagnetic phase of Sr2IrO4
• Thermal conductivity of local moment models with strong spin-orbit coupling
• Spin-polaron ladder spectrum of the spin-orbit-induced Mott insulator Sr${}_2$IrO${}_4$ probed by scanning tunneling spectroscopy