Controlling the density of the 2DEG at the SrTiO3/LaAlO3 interface
| Autor: | Janotti, A., Bjaalie, L., Gordon, L., Van de Walle, C. G. |
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| Rok vydání: | 2012 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.86.241108 |
| Popis: | The polar discontinuity at the SrTiO3/LaAlO3 interface (STO/LAO) can in principle sustain an electron density of 3.3E14 cm-2 (0.5 electrons per unit cell). However, experimentally observed densities are more than an order of magnitude lower. Using a combination of first-principles and Schrodinger-Poisson simulations we show that the problem lies in the asymmetric nature of the structure, i.e., the inability to form a second LAO/STO interface that is a mirror image of the first, or to fully passivate the LAO surface. Our insights apply to oxide interfaces in general, explaining for instance why the SrTiO3/GdTiO3 interface has been found to exhibit the full density of 3.3E14 cm-2. Comment: 5 pages, 3 figures |
| Databáze: | arXiv |
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