Highly Spin-Polarized Conducting State at the Interface between Nonmagnetic Band Insulators:LaAlO3/FeS2(001)

Abstract

First-principles density functional calculations demonstrate that a spin-polarized two-dimensional conducting state can be realized at the interface between two non-magnetic band insulators. The (001) surface of the diamagnetic insulator FeS 2 (pyrite) supports a localized surface state deriving from Fe dorbitals near the conduction band minimum. The deposition of a few unit cells of the polar perovskite oxide LaAlO 3 leads to electron transfer into these surface bands, thereby creating a conducting interface. The occupation of these narrow bands leads to an exchange splitting between the spin sub-bands, yielding a highly spin-polarized conducting state distinct from the rest of the non-magnetic, insulating bulk. Such an interface presents intriguing possibilities for spintronics applications.

Flatbands and Emergent Ferromagnetic Ordering inFe3Sn2Kagome Lattices

“…In the present system, we note that the Stoner parameter I is equivalent to the effective on-site Coulomb interaction U within the hexagonal cell [41]. For bulk Fe 3 Sn 2 , I is roughly 1.15 eV, estimated from dividing the exchange splitting by the magnetic moment [42,43]. It is noticeable that the Hubbard model on the kagome lattice has offered the two mechanisms for ferromagnetism: one is Mielke's flatband ferromagnetism [5][6][7] that is an extreme case of the Stoner instability [44] reducing the potential energy of repulsive electron-electron interactions and the other is Nakaoka-type ferromagnetism [45] due to the gain in the kinetic energy of electrons [46].…”

Spin-moment formation and reduced orbital polarization in LaNiO3/LaAlO3superlattice:LDA+UHan1, Veenendaal2 2012Phys. Rev. B224182View full textAdd to dashboardCite

“…Since the spin polarized oxide heterostructure could be useful for the device appli- cations, there has been active research for finding the structure that produces FM spin order [29][30][31] . Therefore our result of a FM ground state in LNO/LAO may have a positive implication for such an application.…”

Magnetocrystalline anisotropy and its electric-field-assisted switching of Heusler-compound-based perpendicular magnetic tunnel junctions

“…Interfacial spin polarization. The spin-dependent tunneling conductance of the MgObased MTJs is determined by two factors: the symmetry matching between the transmission Bloch states in FM electrodes and evanescent states in the MgO barrier, and the spin polarization (SP) within the electrodes and at the electrode/barrier interfaces [35,[59][60][61][62]. As for the former factor, the spin-filter effect can be tremendously boosted if the FM electrode materials possess half-metallic Δ 1 bands, of which the Bloch states suffer from the smallest decay within the C 4v -symmetry MgO barrier.…”