Almost all oxide two-dimensional electron gases are formed in SrTiO3-based heterostructures and the study of non-SrTiO3 systems is extremely rare. Here, we report the realization of a two-dimensional electron gas in a CaTiO3-based heterostructure, CaTiO3/LaTiO3, grown epitaxially layer-by-layer on a NdGaO3 (110) substrate via pulsed laser deposition. The high quality of the crystal and electronic structures are characterized by in-situ reflection high-energy electron diffraction, X-ray diffraction, and X-ray photoemission spectroscopy. Measurement of electrical transport validates the formation of a two-dimensional electron gas in the CaTiO3/LaTiO3 superlattice. It is revealed the room-temperature carrier mobility in CaTiO3/LaTiO3 is nearly 3 times higher than in CaTiO3/YTiO3, demonstrating the effect of TiO6 octahedral tilts and rotations on carrier mobility of two-dimensional electron gases. Due to doped CaTiO3 being an A-site polar metal, our results provide a new route to design novel A-site two-dimensional polar metals.
@article{arxiv.1811.00180,
title = {Metallic interfaces in a CaTiO$_3$/LaTiO$_3$ heterostructure},
author = {Shaozhu Xiao and Fangdi Wen and Xiaoran Liu and M. Kareev and Yang Song and Ruyi Zhang and Yujuan Pei and Jiachang Bi and Shaolong He and Yanwei Cao and Jak Chakhalian},
journal= {arXiv preprint arXiv:1811.00180},
year = {2020}
}