The intense research activity of physics phenomena at interfaces of solids has resulted in applications that have revolutionized our lifestyle. Probably the most remarkable example is the metal-oxide-semiconductor field-effect transistor (MOSFET) which is found at the heart of every electronic device.

A fascinating interface effect which attracts considerable attention in recent years is the emergence of 2D conductivity at the interface between LaAlO₃ (LAO) and SrTiO₃ (STO). Although both compounds are band insulators, when a LAO film is deposited layer by layer on top of a (001) STO substrate, the interface switches to a metallic state when the film thickness exceeds 3 unit cells. This interesting experimental observation has stimulated intensive experimental and theoretical efforts to identify the origin of the charge carriers and elucidate the properties of this system – a challenging task considering the sensitivity of this system to many parameters such as oxygen pressure during growth, post growth treatment, etc.

The research in the group focuses on several crucial unresolved issues: (a) The existence and nature of the magnetization and its influence on the magnetotransport properties, (b) The discrepancy between the charge carrier density at the LAO/STO interface as extracted by magnetotransport measurements and the carrier density expected based on theoretical considerations which is greater than

an order of magnitude, and similar to the spectroscopic charge density found in X-ray studies, (c) The non-uniformity of transport and magnetic properties on length scales of microns. We have found strong indication for the existence of anisotropic low-temperature nonuniform field-induced magnetization. In addition, we have found clear indications for low-temperature non-uniform charge trapping. The current study in the group follows these findings.

Snir Seri, Moty Schultz, and Lior Klein, Thermally activated recovery of electrical conductivity in LaAlO₃/SrTiO₃, Phys. Rev. B 87, 125110 (2013).

Snir Seri, Moty Schultz, and Lior Klein, Interplay between sheet resistance increase and magnetotransport properties in LaAlO₃/SrTiO₃, Phys. Rev. B 86, 085118 (2012).

Seri, E. Shimshoni, S. Paetel, J. Mannhart, and L. Klein, Angular Dependence of the Magnetoresistance of the SrTiO3/LaAlO3 Interface, IEEE TRANSACTIONS ON MAGNETICS, VOL. 46(6), 1630 (2010).

Snir Seri and Lior Klein, Antisymmetric magnetoresistance of the SrTiO₃/LaAlO₃ interface, Phys. Rev. B 80, 180410(R) (2009).