Large Magnetoresistance in a Manganite Spin-Tunnel-Junction Using LaMnO3 as Insulating Barrier

Abstract

A spin-tunnel-junction based on manganites, with La${}_{1-x}$Sr${}_x$MnO${}_3$ (LSMO) as ferromagnetic metallic electrodes and the undoped parent compound LaMnO${}_3$ (LMO) as insulating barrier, is here theoretically discussed using double exchange model Hamiltonians and numerical techniques. For an even number of LMO layers, the ground state is shown to have anti-parallel LSMO magnetic moments. This highly resistive, but fragile, state is easily destabilized by small magnetic fields, which orient the LSMO moments in the direction of the field. The magnetoresistance associated with this transition is very large, according to Monte Carlo and Density Matrix Renormalization Group studies. The influence of temperature, the case of an odd number of LMO layers, and the differences between LMO and SrTiO${}_3$ as barriers are also addressed. General trends are discussed.

14 pages, 18 figures

References in corpus (18)

• Colossal Magnetoresistant Materials: The Key Role of Phase Separation
• The density-matrix renormalization group
• Complexity in Strongly Correlated Electronic Systems
• Why Some Interfaces Cannot be Sharp
• Real time evolution using the density matrix renormalization group
• Nearly total spin polarization in La2/3Sr1/3MnO3 from tunneling experiments
• Phase Separation in Electronic Models for Manganites
• Extrinsic Magnetotransport Phenomena in Ferromagnetic Oxides
• Oxide spintronics
• New Trends in Density Matrix Renormalization
• Lattice relaxation, electronic screening, and spin and orbital phase diagram of LaTiO${}_3$/SrTiO${}_3$ superlattices
• Competing Ferromagnetic and Charge-Ordered States in Models for Manganites: the Origin of the CMR Effect
• Electron Doping of Cuprates via Interfaces with Manganites
• Static and Dynamical Properties of the Ferromagnetic Kondo Model with Direct Antiferromagnetic Coupling Between the localized $t_{2g}$ Electrons
• Applying Adaptive Time-Dependent DMRG to Calculate the Conductance of Strongly Correlated Nanostructures
• Computational implementation of the Kubo formula for the static conductance: application to two-dimensional quantum dots
• Magnetoresistance in an all-manganite heterostructure
• Anderson impurity in the one-dimensional Hubbard model on finite size systems

Cited by in corpus (5)

• Metal-insulator transition in $(LaMn{O}_3{)}_{2n}/(SrMn{O}_3{)}_n$ superlattices
• Quantum Phases of the Shastry-Sutherland Kondo Lattice: Implications for the Global Phase Diagram of Heavy Fermion Metals
• Electronic and Magnetic Properties of ${\mathrm{RMnO}}_3/{\mathrm{AMnO}}_3$ Heterostructures
• Neutron scattering study of magnetic phase separation in nanocrystalline La${}_{5/8}$Ca${}_{3/8}$MnO${}_3$
• Surface magnetic phase transition of the double-exchange ferromagnet: Schwinger-boson mean-field study