Seminar Maria D´Antuono, 18.7.2018 at 13:00
Magnetotransport properties of 2DEG formed in LAO/ETO/STO heterostructures studies using the electric field effect
Maria D´Antuono, University of Naples Federico II, Naples, Italy
Wednesday, 18.7.2018 at 13:00 in the seminar room of the Department of complex matter F7
In 2004 Ohtomo and Hwang  reported the formation of a high mobility 2-dimensional electron gas (2DEG) at the interface between two wide bandgap insulators oxides, namely LaAlO3 (LAO) and SrTiO3 (STO). In this work, we show that the 2DEG created at the LAO/STO interface becomes both electric-field-tunable spin polarized and superconducting by introducing a few atomic layers of EuTiO3 (ETO) which is an antiferromagnetic (AF) insulator iso-structural to STO . Among the most interesting characteristics of this 2DEG are the remarkably large Rashba-spin-orbit interactions and unconventional superconductivity and magnetism, possibly related to the presence of strong correlations in quantum-confined 3d-bands . The occurrence of magnetic interactions, superconductivity and spin-orbit interactions in the same 2DEG system makes the LAO/ETO/STO an intriguing platform for the emergence of novel quantum phases in low-dimensional devices. The main goal of this work was to investigate the electrical transport of the LAO/ETO/STO interface and to shed more light on the complex nature of this system and its phase diagram. In particular, we focused on the interplay between Rashba-spin-orbit interactions and ferromagnetism. In fact, the LAO/ETO/STO 2DEG is one of the few systems where such interplay can be studied and it is therefore of great interest for future spintronic applications.
 A. Ohtomo and H. Y.Hwang, “A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface.” Nature 427, (2004);
 G. M. De Luca, D. Stornaiuolo et al. “Transport properties of a quasi two-dimensional electron system formed in LaAlO3/EuTiO3/SrTiO3 heterostructures”, Phy. Rev. B 89, 224413 (2014);
 D. Stornaiuolo et al. “Tunable spin polarization and superconductivity in engineered oxide interfaces”, Nature Mat. 10.1038 4491 (2015).