Impact of electric-field dependent dielectric constants on two-dimensional electron gases in complex oxides
Journal article, 2015

High-density two-dimensional electron gas (2DEG) can be formed at complex oxide interfaces such as SrTiO3/GdTiO3 and SrTiO3/LaAlO3. The electric field in the vicinity of the interface depends on the dielectric properties of the material as well as on the electron distribution. However, it is known that electric fields can strongly modify the dielectric constant of SrTiO3 as well as other complex oxides. Solving the electrostatic problem thus requires a self-consistent approach in which the dielectric constant varies according to the local magnitude of the field. We have implemented the field dependence of the dielectric constant in a Schrodinger-Poisson solver in order to study its effect on the electron distribution in a 2DEG. Using the SrTiO3/GdTiO3 interface as an example, we demonstrate that including the field dependence results in the 2DEG being confined closer to the interface compared to assuming a single field-independent value for the dielectric constant. Our conclusions also apply to SrTiO3/LaAlO3 as well as other similar interfaces.


H. Peelaers

University of California

K. Krishnaswamy

University of California

L. Gordon

University of California

D. Steiauf

University of California

Anna Sarwe

Student at Chalmers

A. Janotti

University of California

University of Delaware

C. G. Van de Walle

University of California

Applied Physics Letters

0003-6951 (ISSN) 1077-3118 (eISSN)

Vol. 107 18 4- 183505

Subject Categories

Physical Sciences



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