In solid-state physics, oxide layers only a few nanometres thick are known to form a so-called two-dimensional electron gas. These thin layers, separated from one another, are transparent and electrically insulating materials. However, when one thin layer grows on top of the other, a conductive area forms under certain conditions at the interface, which has a metallic shine. "Normally this system remains non-magnetic," says Professor Ingrid Mertig from the Institute of Physics at MLU. The research team has succeeded in controlling conditions during layer growth so that vacancies are created in the atomic layers near the interface. These are later filled in by other atoms from adjoining atomic layers.

The theoretical calculations and explanations for this newly discovered phenomenon were made by Ingrid Mertig's team of physicists. The method was then experimentally tested by several research groups throughout Europe -- including a group led by Professor Kathrin Dörr from MLU. They were able to prove the magnetism in the materials. "This combination of computer simulations and experiments enabled us to decipher the complex mechanism responsible for the development of magnetism," explains Mertig.

Story Source:

Materials provided by Martin-Luther-Universität Halle-Wittenberg. Note: Content may be edited for style and length.

Journal Reference:

1. D.-S. Park, A. D. Rata, I. V. Maznichenko, S. Ostanin, Y. L. Gan, S. Agrestini, G. J. Rees, M. Walker, J. Li, J. Herrero-Martin, G. Singh, Z. Luo, A. Bhatnagar, Y. Z. Chen, V. Tileli, P. Muralt, A. Kalaboukhov, I. Mertig, K. Dörr, A. Ernst, N. Pryds. The emergence of magnetic ordering at complex oxide interfaces tuned by defects. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-17377-0