Observation of non-Fermi liquid behaviors on high-mobility LaNiO₃

LaNiO₃ (LNO) is a special member of the rare-earth perovskite nickelate family, as it does not show metal-insulator or magnetic transitions at low temperatures. Whether or not LNO behaves like a Fermi liquid in the low temperature regime with quadratic temperature dependence of resistivity remains an open question. Recent measurements of the electronic structure and theoretical calculations support the presence of structural and magnetic instabilities in LNO. However, the impact of these instabilities has yet to be clarified in transport measurements, partly because preparing high-quality LNO samples had been challenging due to a propensity towards oxygen vacancy formation. Here, we report on the observation of non-Fermi liquid transport behaviors at sub-Kelvin temperatures in high-mobility LNO thin films grown by ozone-assisted molecular beam epitaxy. The resistivity of these samples can be lower than 4 μΩ cm at T = 2 K, with residual resistivity ratios (RRR) [ρ (300 K) / ρ (2 K)] > 24.