Figure 1

Structure of the $5/3$ ${\mathrm{TiO}}_2/{\mathrm{VO}}_2$ supercell corresponding to growth along the (001) axis, which is the metal chain direction of the rutile structure. V1, V2, and V3 label the V ion sites beginning from the one nearest to ${\mathrm{TiO}}_2$. (Because of a symmetry with respect to the center of the ${\mathrm{VO}}_2$ slab, the V layers are V1-V2-V3-V3-V2-V1.)Reuse & Permissions

Figure 2

Total density of states in the $5/3$ multilayer, showing the location of the V and Ti bands relative to those of O (which are unpolarized). The V occupied majority spin bands (plotted upward) lie within a 2 eV gap in the minority spin.Reuse & Permissions

Figure 3

Left panel: Blowup of the band structure around the Fermi level showing in different colors the biggest character of each band. Notice that the two bands crossing at the Fermi level have character from the two most inner V atoms. Note the semi-Dirac-point along the (110) direction where bands cross precisely at the Fermi level. Middle panel: Two different views of the same “surface” plot of the two bands that cross the Fermi level, centered around the semi-Dirac-point. The valence and conduction bands cross at a single point. The linear dispersion can be seen in the upper plot (upper left and lower right); the quadratic dispersion is clear in the lower panel, where the flatness of the conduction band is also clear. Right panel: Contour plots at constant energy (in eV, relative to the Fermi level) of the valence band (below), and the flat conduction band (above) that leads to large $M$-centered Fermi surfaces for electron doping.Reuse & Permissions

Figure 4

Spin density plot, isosurface at $0.15\mathrm{e}/{\AA }^3$. The particular orbital ordering in a spin-aligned configuration is shown. V1 and V2 have one electron in a $d_{\parallel }$, and V3 is in a $d_{\perp }$ orbital.Reuse & Permissions