Resonant electronic states and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>I</mml:mi><mml:mtext>−</mml:mtext><mml:mi>V</mml:mi></mml:mrow></mml:math>curves of Fe/MgO/Fe(100) tunnel junctions

Rungger, Ivan; Mryasov, O. N.; Sanvito, Stefano

doi:10.1103/physrevb.79.094414

Cited by 65 publications

(70 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The I -V characteristics are calculated non-self-consistently by evaluating the transmission coefficient over an effective bias-dependent Hamiltonian matrix, which in turn is obtained by adding a rigid shift to the zero-bias Hamiltonian matrix elements of the electrodes and a linear potential across the insulating barrier. This is a good approximation to the selfconsistent potential drop for tunnel junctions, 6 which appears essentially like that of a standard parallel-plate capacitor.…”

Section: Methodsmentioning

confidence: 99%

“…3 The high TMR 4,5 found in Fe/MgO-based junctions is caused by the symmetry filtering provided by the MgO barrier, together with the particular spin polarization of the Fe electrodes. Only electrons with 1 symmetry and with small transverse momentum contribute significantly to the current [6][7][8][9][10][11][12] through MgO, and in Fe these are found only in the majority spins for electrons at the Fermi energy, so that the Fe/MgO stack acts like a spin filter in the current flow. For energies around the Fermi energy, E F , these are found only in the majority Fe states.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electronic transport through EuO spin-filter tunnel junctions

et al. 2012

Self Cite

View full text Add to dashboard Cite

Epitaxial spin-filter tunnel junctions based on the ferromagnetic semiconductor europium monoxide (EuO) are investigated by means of density functional theory. In particular, we focus on the spin transport properties of Cu(100)/EuO(100)/Cu(100) junctions. The dependence of the transmission coefficient and the current-voltage curves on the interface spacing and EuO thickness is explained in terms of the EuO density of states and the complex band structure. Furthermore, we also discuss the relation between the spin transport properties and the Cu-EuO interface geometry. The level alignment of the junction is sensitively affected by the interface spacing, since this determines the charge transfer between EuO and the Cu electrodes. Our calculations indicate that EuO epitaxially grown on Cu can act as a perfect spin filter, with a spin polarization of the current close to 100%, and with both the Eu-5d conduction-band and the Eu-4f valence-band states contributing to the coherent transport. For epitaxial EuO on Cu, a symmetry filtering is observed, with the 1 states dominating the transmission. This leads to a transport gap larger than the fundamental EuO band gap. Importantly, the high spin polarization of the current is preserved up to large bias voltages.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electronic transport through EuO spin-filter tunnel junctions

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the theory side, interface resonance states ͑IRSs͒ located around the Fermi energy ͑E F ͒ are important for the zero-bias transport 5 and are usually difficult to describe accurately. Moreover the MgO bandgap is significantly underestimated by local spin-density approximation ͑LSDA͒ and generalized gradient approximation ͑GGA͒ so that the barrier height might not be accurately predicted.…”

Section: Introductionmentioning

confidence: 99%

Effects of structural relaxation on calculations of the interface and transport properties of Fe/MgO(001) tunnel junctions

et al. 2009

View full text Add to dashboard Cite

The relaxation of the interface structure of Fe/MgO͑100͒ magnetic tunnel junctions predicted by densityfunctional theory depends significantly on the choice of exchange and correlation functional. Bader analysis reveals that structures obtained by relaxing the cell with the local spin-density approximation ͑LSDA͒ display a different charge transfer than those relaxed with the generalized gradient approximation ͑GGA͒. As a consequence, the electronic transport is found to be extremely sensitive to the interface structure. In particular, the conductance for the LSDA-relaxed geometry is about 1 order of magnitude smaller than that of the GGArelaxed one. Surprisingly, the effect of the exchange and correlation potential within both the LSDA and the GGA has a little effect on the calculated transmission coefficient when applied to the same Fe/MgO/Fe ͑001͒ geometry. The high sensitivity of the electronic current to the details of the relaxed interface might explain the discrepancy between the experimental and calculated values of magnetoresistance.

show abstract

“…[1][2][3][4][5] However, more recent applications also include graphene nanoribbons, [6][7][8] semiconducting and metallic nanowires, [9][10][11] and bulk tunneling junctions for magnetoresistance and electrochemical applications. 12,13 The rapid developments in these areas toward atomic-scale control of interface structures, and the continuing miniaturization of electronics components makes the development of efficient and flexible computational tools for the description of charge transport at the nanoscale an important endeavor.…”

Section: Introductionmentioning

confidence: 99%

Ab initiononequilibrium quantum transport and forces with the real-space projector augmented wave method

2012

View full text Add to dashboard Cite

We present an efficient implemention of a non-equilibrium Green function (NEGF) method for selfconsistent calculations of electron transport and forces in nanostructured materials. The electronic structure is described at the level of density functional theory (DFT) using the projector augmented wave method (PAW) to describe the ionic cores and an atomic orbital basis set for the valence electrons. External bias and gate voltages are treated in a self-consistent manner and the Poisson equation with appropriate boundary conditions is solved in real space. Contour integration of the Green function and parallelization over k-points and real space makes the code highly efficient and applicable to systems containing several hundreds of atoms. The method is applied to a number of different systems demonstrating the effects of bias and gate voltages, multiterminal setups, nonequilibrium forces, and spin transport.

show abstract

Resonant electronic states andI−Vcurves of Fe/MgO/Fe(100) tunnel junctions

Cited by 65 publications

References 19 publications

Electronic transport through EuO spin-filter tunnel junctions

Electronic transport through EuO spin-filter tunnel junctions

Effects of structural relaxation on calculations of the interface and transport properties of Fe/MgO(001) tunnel junctions

Ab initiononequilibrium quantum transport and forces with the real-space projector augmented wave method

Contact Info

Product

Resources

About