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Magnetothemopower study of quasi two-dimensional organic conductor $α$-(BEDT-TTF)$_2$KHg(SCN)$_4$

E. S. Choi·J. S. Brooks·J. S. Qualls
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Abstract

We have used a low-frequency magneto-thermopower (MTEP) method to probe the high magnetic field ground state behavior of $α$-(BEDT-TTF)$_2$KHg(SCN)$_4$ along all three principal crystallographic axes at low temperatures. The thermopower tensor coefficients ($S_{xx}, S_{yx}$ and $S_{zz}$) have been measured to 30 T, beyond the anomalous low temperature, field-induced transition at 22.5 T. We find a significant anisotropy in the MTEP signal, and also observe large quantum oscillations associated with the de Haas - van Alphen effect. The anisotropy indicates that the ground state properties are clearly driven by mechanisms that occur along specific directions for the in-plane electronic structure. Both transverse and longitudinal magnetothermopower show asymptotic behavior in field, which can be explained in terms of magnetic breakdown of compensated closed orbits.

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E. S. Choi, J. S. Brooks, J. S. Qualls. 2001-04-24. Magnetothemopower study of quasi two-dimensional organic conductor $α$-(BEDT-TTF)$_2$KHg(SCN)$_4$. https://doi.org/10.1103/physrevb.65.205119

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