High Mobility Two-Dimensional Electron Gas in PbZr_0.5Ti_0.5O₃/BaSnO₃ Heterostructure

The two-dimensional electron gas (2DEG) formed at oxide heterointerface between LaAlO₃ and SrTiO₃ has been attracting fundamental and practical attention due to its novel quantum properties and interfacial conductivity. However, these 2DEGs reside in weakly dispersive Ti-d bands, and the mobility of 2DEG is relatively low at room temperature, which limit its future application. Here, in order to enhance 2DEG mobility, we consider a novel BaSnO₃ with highly dispersive conduction Sn-5s band. Using the first-principles calculations, we find that the n-type 2DEG can be formed at PbZr_0.5Ti_0.5O₃/BaSnO₃ heterostructure. Our results show that the 2DEG produced by polar field resides within the highly dispersive Sn-5s band and its mobility is expected to be several times higher than that in LAO/STO.