Interface-Driven Ferromagnetism within the Quantum Wells of a Rare Earth Titanate Superlattice

Published

July 15, 2016

Author(s)

R. F. Need, B. J. Isaac, Brian Kirby, Julie Borchers, S. Stemmer, Stephen D. Wilson

Abstract

The lure of imparting many-body strong correlation effects into conventional electronic states via interface effects underlies the exploration of numerous transition metal oxide heterostructures for both future devices as well as fundamental scientific inquiry. Here we present a polarized neutron reflectometry study revealing the propagation of spin order across the interface between a strongly correlated, magnetic Mott state (GdTiO₃) and into a conventional, naively nonmagnetic, band insulator (SrTiO₃). Reflectometry data show that magnetic order is induced throughout the volume of SrTiO₃ quantum wells embedded within a GdTiO₃ matrix until a critical well thickness is reached. Below this critical thickness, the induced magnetic order within the quantum wells comprises the likely origin of quantum critical magnetotransport in this thin film architecture. More broadly, our results present a novel observation of spin order imparted throughout a nonmagnetic medium and stabilized via the cooperative interplay between extended interface charge and proximate molecular exchange fields.

Citation

Physical Review Letters

Volume

117

Issue

3

Pub Type

Journals

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Keywords

neutron reflectometry, complex oxides

Citation

Need, R. , Isaac, B. , Kirby, B. , Borchers, J. , Stemmer, S. and Wilson, S. (2016), Interface-Driven Ferromagnetism within the Quantum Wells of a Rare Earth Titanate Superlattice, Physical Review Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=920326 (Accessed May 18, 2024)