title: Controlling spin-dependent tunneling by bandgap tuning in epitaxial rocksalt MgZnO films.
abstract: Widespread application of magnetic tunnel junctions (MTJs) for information storage has so far been limited by the complicated interplay between tunnel magnetoresistance (TMR) ratio and the product of resistance and junction area (RA). An intricate connection exists between TMR ratio, RA value and the bandgap and crystal structure of the barrier, a connection that must be unravelled to optimise device performance and enable further applications to be developed. Here, we demonstrate a novel method to tailor the bandgap of an ultrathin, epitaxial Zn-doped MgO tunnel barrier with rocksalt structure. This structure is attractive due to its good Δ1 spin filtering effect, and we show that MTJs based on tunable MgZnO barriers allow effective balancing of TMR ratio and RA value. In this way spin-dependent transport properties can be controlled, a key challenge for the development of spintronic devices.
authors.affiliation: State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: D L
authors.initials: DL
authors.lastname: Li
authors.affiliation: State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Q L
authors.initials: QL
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: S G
authors.initials: SG
authors.lastname: Wang
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK.
authors.forename: R C C
authors.initials: RC
authors.lastname: Ward
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK.
authors.forename: T
authors.initials: T
authors.lastname: Hesjedal
authors.affiliation: 1] Department of Physics and Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA [2] Center for Nanophase Materials Sciences and Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6493, USA.
authors.forename: X-G
authors.initials: XG
authors.lastname: Zhang
authors.affiliation: Department of Materials Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Kohn
authors.affiliation: Department of Materials Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: E
authors.initials: E
authors.lastname: Amsellem
authors.affiliation: State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: G
authors.initials: G
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: J L
authors.initials: JL
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: J
authors.initials: J
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: H X
authors.initials: HX
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: X F
authors.initials: XF
authors.lastname: Han