Scientists observed an antiferromagnetic quantum critical point (QCP) in high-purity LaNiO3.
Significance and Impact
At a QCP, fluctuations of the order parameter can have a profound influence on the properties of a material, such as a breakdown of the Landau Fermi liquid, leading to a “strange metal” with anomalous transport and thermodynamic properties.
- LaNiO3 thin films with unprecedented high purities are prepared using oxide molecular beam epitaxy.
- Transport measurements reveal a linear dependence of the resistivity with temperature over nearly a decade for T ≤ 1.1 K. Fermi liquid behavior is restored in a large magnetic field when quantum critical fluctuations are suppressed.
- A series of samples with varying levels of disorder show the predicted behavior of the resistivity near a QCP as a function of temperature, as well as a magnetoresistance arising from scattering by local magnetic moments.
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