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arXiv · 1611.07683

Absence of magnetic thermal conductivity in the quantum spin liquid candidate YbMgGaO4

Y. Xu·J. Zhang·Y. S. Li·Y. J. Yu·X. C. Hong·Q. M. Zhang·S. Y. Li
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Abstract

We present the ultra-low-temperature specific heat and thermal conductivity measurements on the single crystals of YbMgGaO$_4$, which was recently argued to be a promising candidate for quantum spin liquid (QSL). In the zero magnetic field, a large magnetic contribution of specific heat is observed, and exhibits a power-law temperature dependence ($C_m \sim T^{0.74}$). On the contrary, we do not observed any significant contribution of thermal conductivity from magnetic excitations. In magnetic fields $H \ge$ 6 T, the exponential $T$-dependence of $C_m$ and the enhanced thermal conductivity indicate a magnon gap of the fully-polarized state. The absence of magnetic thermal conductivity at the zero field in this QSL candidate puts a strong constraint on the theories of its ground state.

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Y. Xu, J. Zhang, Y. S. Li, Y. J. Yu, X. C. Hong, Q. M. Zhang, S. Y. Li. 2016-11-23. Absence of magnetic thermal conductivity in the quantum spin liquid candidate YbMgGaO4. https://doi.org/10.1103/physrevlett.117.267202

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