The phenomenological theory for the polar instability giving rise to a two-dimensional electron gas at perovskite interfaces is hereby extended to include the coupling to perovskite tilts. A Landau theory for homogeneous tilts is first explored, setting the scene for the further, more realistic Landau-Ginzburg theory describing varying tilt amplitudes across a thin film. The theory is also generalized to account for the response to an applied electric field normal to the interface, which allows a finer control on phase transitions. The conventionally described physics of a single metal-insulator transition is substantially enriched by the coupling, the model describing various scenarios with one or two transitions, possibly continuous or discontinuous. First-principles calculations permit the estimation of the parameters defining the model, which have been calculated for the interface between lanthanum aluminate and strontium titanate.

中文翻译：

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极性 - 非极性钙钛矿界面处的倾斜和电荷载流子之间的耦合

在钙钛矿界面处产生二维电子气的极性不稳定性的唯象理论被扩展为包括与钙钛矿倾斜的耦合。首先探索了均匀倾斜的朗道理论，为描述薄膜上不同倾斜幅度的更真实的朗道-金茨堡理论奠定了基础。该理论也被推广到解释垂直于界面的施加电场的响应，这允许对相变进行更精细的控制。传统上描述的单个金属-绝缘体过渡的物理特性通过耦合大大丰富，该模型描述了具有一个或两个过渡的各种场景，可能是连续的或不连续的。第一性原理计算允许估计定义模型的参数，