Lecturer: Dr. Jonathan Ruhman Affiliation: Department of Condensed-matter Physics, Weizmann institute of Science Abstract: Measurements performed on the two- dimensional metallic interface between LaAlO3 and SrTiO3 indicate that a magnetic transition occurs when the density of conduction electrons is tuned in the presence of a magnetic field [1, 2]. For example, magneto-transport measurements find that the resistance drops sharply exactly where an anomalous Hall effect develops and the resistivity becomes anisotropic. The main questions I deal with in this talk are: What is the nature of these phases? and why does the transition between them depend on the density of conduction electrons? To answer these questions I construct a minimal model consisting of two essential ingredients: a conduction band Hamiltonian describing the metallic states and localized magnetic moments which reside near the interface. I show that the magnetic transition observed in experiment can be explained in terms of a transition between a state where the moments are Kondo screened and their magnetization is suppressed, and a state where the Kondo screening breaks down and the moments polarize along the magnetic field. This model allows me to construct a global phase diagram that unifies a variety of experiments and theoretical models. [1] Joshua et. al. PNAS 9633 110 (2013) [2] Bi et. al. Nature Communications 5, 5019 (2014) ‏האירוע הזה כולל שיחת וידאו ב-Google Hangouts. הצטרף: https://hangouts.google.com/hangouts/_/mail.huji.ac.il/condensed?hceid=b...