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arXiv · 2011.11535

From hidden metal-insulator transition to Planckian-like dissipation by tuning disorder in a nickelate

Qikai Guo·Beatriz Noheda
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Abstract

Heavily oxygen deficient NdNiO$_3$ (NNO) films, which are insulating due to electron localization, contain pristine regions that undergo a hidden metal-insulator transition. Increasing oxygen content increases the connectivity of the metallic regions and the metal-insulator transition is first revealed, upon reaching the percolation threshold, by the presence of hysteresis. Only upon further oxygenation is the global metallic state (with a change in the resistivity slope) eventually achieved. It is shown that sufficient oxygenation leads to linear temperature dependence of resistivity in the metallic state, with a scattering rate directly proportional to temperature. Despite the known difficulties to establish the proportionality constant, the experiments are consistent with a relationship 1/$\tau$= $\alpha k_B T/\hbar$, with $\alpha$ not far from unity. These results could provide experimental support for recent theoretical predictions of disorder in a two-fluid model as a possible origin of Planckian dissipation.

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Qikai Guo, Beatriz Noheda. 2020-11-23. From hidden metal-insulator transition to Planckian-like dissipation by tuning disorder in a nickelate. https://doi.org/10.1038/s41535-021-00374-x

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