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Title: Electrical properties and subband occupancy at the (La, Sr)(Al, Ta)O3/SrTiO3 interface
Authors: Han, K.
Huang, Z.
Zeng, S. W.
Yang, M.
Li, C. J.
Zhou, W. X.
Wang, Renshaw Xiao
Venkatesan, T.
Coey, J. M. D.
Goiran, M.
Escoffier, W.
Keywords: Electronic Structure
Hall Effect
Issue Date: 2017
Source: Han, K., Huang, Z., Zeng, S. W., Yang, M., Li, C. J., Zhou, W. X., . . . Ariando. (2017). Electrical properties and subband occupancy at the (La, Sr)(Al, Ta)O3/SrTiO3 interface. Physical Review Materials, 1(1), 011601-. doi:10.1103/PhysRevMaterials.1.011601
Series/Report no.: Physical Review Materials
Abstract: The quasi-two-dimensional electron gas at oxide interfaces provides a platform for investigating quantum phenomena in strongly correlated electronic systems. Here, we study the transport properties at the high-mobility (La0.3Sr0.7) (Al0.65Ta0.35) O3/SrTiO3 interface. Before oxygen annealing, the as-grown interface exhibits a high electron density and electron occupancy of two subbands: higher-mobility electrons (μ1≈10^4 cm2 V−1s−1 at 2 K) occupy the lower-energy 3dxy subband, while lower-mobility electrons (μ1≈103cm2V−1s−1 at 2 K) propagate in the higher-energy 3dxz/yz-dominated subband. After removing oxygen vacancies by annealing in oxygen, only a single type of 3dxy electrons remain at the annealed interface, showing tunable Shubnikov–de Haas oscillations below 9 T at 2 K and an effective mass of 0.7me. By contrast, no oscillation is observed at the as-grown interface even when electron mobility is increased to 50 000 cm2V−1s−1 by gating voltage. Our results reveal the important roles of both carrier mobility and subband occupancy in tuning the quantum transport at oxide interfaces.
DOI: 10.1103/PhysRevMaterials.1.011601
Rights: © 2017 American Physical Society. All rights reserved. This paper was published in Physical Review Materials and is made available with permission of American Physical Society.
Fulltext Permission: open
Fulltext Availability: With Fulltext
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