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TT: Fachverband Tiefe Temperaturen

TT 58: SrTiO₃: A Versatile Material from Bulk Quantum Paraelectric to 2D Superconductor: Poster (joint session TT/KFM/MA/O)

TT 58.7: Poster

Wednesday, March 20, 2024, 15:00–18:00, Poster E

Impact of a Si(001) substrate on the electronic reconstruction and two-dimensional electron gas formation at LaTiO₃/SrTiO₃(001) — •Andri Darmawan and Rossitza Pentcheva — Department of Physics, University of Duisburg-Essen

The two-dimensional electron gas (2DEG) formed at oxide interfaces e.g. between the band insulator SrTiO₃ and the Mott insulator LaTiO₃ has attracted a lot of attention [1]. However, despite the high carrier density at the interface, the carrier mobility is lower compared to semiconductor materials. A strategy to overcome this shortcoming is the integration of the oxide system on a semiconductor substrate [2]. Based on density functional theory calculations with a Hubbard U term we modeled LaTiO₃/SrTiO₃(001) with and without a Si(001) substrate. We explore systematically the sample geometry and the effect of the termination to Si(001) on the electronic reconstruction at the LaTiO₃/SrTiO₃(001) interface. The comparison between the two systems indicates lower effective masses and consequently higher mobility of the 2DEG at LaTiO₃/SrTiO₃/Si(001).

Funding by DFG within CRC1242 and computational time at the Leibniz Supercomputer Center (project pr87ro) are gratefully acknowledged.

[1] A. Ohtomo et al., Nature 419, 378 (2002)

[2] E. N. Jin et al., APL Mater. 2, 116109 (2014)

Keywords: density functional theory; two-dimensional electron gas; oxide interfaces; silicon