The ferroelectric field effect on the two-dimensional electron gas at LaAlO3/SrTiO3 (001) interface: Insights from first principle simulations

• The ferroelectric field has a great effect on the carrier density of the interface.
• The polarization in left SrTiO3 screens the polar discontinuity at the interface.
• The carrier density at the interface is determined by the electrical field in LaAlO3.

We perform first-principles calculations to explore the possibility of tuning the two-dimensional electron gas at the LaAlO3/SrTiO3 (001) interface through BaTiO3 substrate. A metal-to-insulator transition is found at the interface as the polarization of BaTiO3 reverses. Through the potential analysis of the LaAlO3/SrTiO3/BaTiO3 superstructure, we find that the intrinsic electric field of LaAlO3 is significantly suppressed as the polarization points away from the LaAlO3/SrTiO3 interface, while it is enhanced with the polarization pointing to the interface. The ferroelectric field control of the intrinsic electric field, and therefore the electronic reconstructions at the interface, originating from the screening of polarization charges, opens the way to the development of novel nanoscale electronic devices.

Using first-principle DFT method, we demonstrate the ferroelectric field effect on the 2DEG at the LaAlO3/SrTiO3 (001) interface, which may suggest new possibilities to tune the 2DEG at the interface and new paths to develop high performance transistors.Figure optionsDownload as PowerPoint slide