Strain-induced continuous transition from Weak localization regime to Strong localization regime in a doped Mott Insulator

We report electrical transport properties of the Nd_0.7La_0.3NiO₃ films (thickness 80 nm) measured down to 300 mK which were grown on LaAlO₃ (100), SrTiO₃ (100), and NdGaO₃ (100) single crystal substrates by pulsed laser deposition. We show that strain/strain inhomogeneity induced by the substrates can lead to a continuous transition from the weak localized regime to a strong localized regime and likelihood of occurrence of a non- Fermi liquid behavior. We observed that the metallic state of a film under compressive strain shows the non- Fermi liquid behavior while the film that experiences a tensile strain shows a metal-insulator transition and a Fermi liquid behavior. The disorder induced continuous transition has been proposed in the context of half-filled Anderson Hubbard model at a finite temperature where the quenched disorder as well auxiliary field fluctuations is responsible for non-Fermi liquid scaling ¹ . It is likely that strain inhomogeneity in such films acts as a quenched disorder.

References
1. Niravkumar D. Patel, Anamitra Mukherjee, Nitin Kaushal, Adriana Moreo, and Elbio Dagotto, Phys. Rev. Lett. 119, 086601 (2017).