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arXiv · 1811.00180

Metallic interfaces in a CaTiO$_3$/LaTiO$_3$ heterostructure

Shaozhu Xiao·Fangdi Wen·Xiaoran Liu·M. Kareev·Yang Song·Ruyi Zhang·Yujuan Pei·Jiachang Bi·Shaolong He·Yanwei Cao·Jak Chakhalian
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Abstract

Almost all oxide two-dimensional electron gases are formed in SrTiO$_3$-based heterostructures and the study of non-SrTiO$_3$ systems is extremely rare. Here, we report the realization of a two-dimensional electron gas in a CaTiO$_3$-based heterostructure, CaTiO$_3$/LaTiO$_3$, grown epitaxially layer-by-layer on a NdGaO$_3$ (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 CaTiO$_3$/LaTiO$_3$ superlattice. It is revealed the room-temperature carrier mobility in CaTiO$_3$/LaTiO$_3$ is nearly 3 times higher than in CaTiO$_3$/YTiO$_3$, demonstrating the effect of TiO$_6$ octahedral tilts and rotations on carrier mobility of two-dimensional electron gases. Due to doped CaTiO$_3$ being an A-site polar metal, our results provide a new route to design novel A-site two-dimensional polar metals.

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Shaozhu Xiao, Fangdi Wen, Xiaoran Liu, M. Kareev, Yang Song, Ruyi Zhang, Yujuan Pei, Jiachang Bi, Shaolong He, Yanwei Cao, Jak Chakhalian. 2018-11-01. Metallic interfaces in a CaTiO$_3$/LaTiO$_3$ heterostructure. https://doi.org/10.1103/physrevmaterials.4.104008

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