title: Tuning bad metal and non-Fermi liquid behavior in a Mott material: Rare-earth nickelate thin films.
abstract: Resistances that exceed the Mott-Ioffe-Regel limit (known as bad metal behavior) and non-Fermi liquid behavior are ubiquitous features of the normal state of many strongly correlated materials. We establish the conditions that lead to bad metal and non-Fermi liquid phases in NdNiO3, which exhibits a prototype bandwidth-controlled metal-insulator transition. We show that resistance saturation is determined by the magnitude of Ni eg orbital splitting, which can be tuned by strain in epitaxial films, causing the appearance of bad metal behavior under certain conditions. The results shed light on the nature of a crossover to a non-Fermi liquid metal phase and provide a predictive criterion for Anderson localization. They elucidate a seemingly complex phase behavior as a function of film strain and confinement and provide guidelines for orbital engineering and novel devices.
authors.affiliation: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Mikheev
authors.affiliation: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Hauser
authors.affiliation: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors.forename: Burak
authors.initials: B
authors.lastname: Himmetoglu
authors.affiliation: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors.forename: Nelson E
authors.initials: NE
authors.lastname: Moreno
authors.affiliation: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors.forename: Anderson
authors.initials: A
authors.lastname: Janotti
authors.affiliation: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors.forename: Chris G
authors.initials: CG
authors.lastname: Van de Walle
authors.affiliation: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors.forename: Susanne
authors.initials: S
authors.lastname: Stemmer
keywords: Non-Fermi liquide; bad metals; quantum criticality; strange metals