APS/Alan Stonebraker

Figure 1: (a) Lattice structure of the $STO$-$LAO$ interface, showing the unpoled $SrO$ and $TiO2$ planes in $STO$ as well as the $LaO+$ and $AlO2-$ planes with alternating polarity in $LAO$. (b) Simulation of the $LAO$ overlayer by an electrolytic gel with frozen-in polarization, allowing for controlled tuning of the charge-carrier density in the two-dimensional electron gas. The diagrams to the right of (a) and (b) show the potential energy of the $LAO$ overlayer and of the polarized gel, respectively, increasing linearly with layer thickness.