Abstract

Bulk SrTiO3 is on the border of ferroelectricity at low temperatures, and can be doped to create an extremely low density superconductor with high electron mobility. These unique properties have motivated the recent interest in low dimensional SrTiO3 heterostructures. The 2D superconductivity at the asymmetrically confined LaAlO3/SrTiO3 interface [1], and in particular its control with an electrostatic field effect gate [2, 3], is a paradigmatic example where we can explore novel low dimensional physics.

Most intriguingly, real space imaging by scanning SQUID microscopy [4], as well as spectroscopic studies [5], reveal emergent magnetism simultaneously with superconductivity. I will discuss the possible mechanisms at play that give rise to the fascinating physics in this system.

[1] A. Ohtomo and H. Y. Hwang, Nature 427, 423 (2004). [2] A. D. Caviglia et al., Nature 456, 624 (2008). [3] C. Bell et al., Phys. Rev. Lett. 103, 226802 (2009). [4] J. Bert et al., Nature Phys. 7, 767 (2011). [5] J.-S. Lee et al., Nature Mater. (accepted).