Interfacial superconductivity in the LaAlO3/SrTiO3 system

The interface between LaAlO3 and SrTiO3, two good band insulators, was found in 2004 to be conducting [1], and, in some doping range, superconducting with a maximum critical temperature of about 300 mK [2,3]. I will discuss in this presentation the electronic structure of the 2D electron liquid, superconductivity, and the phase diagram of the system. I will then compare superconductivity at the interface and in bulk doped SrTiO3 [4]. Open questions, including the origin of superconductivity in doped SrTiO3 and at the LaAlO3/SrTiO3 interface, signatures of spin-orbit, and the underdoped regime for which tunneling data suggest an unusual behavior [5], will be addressed.
 
References:
[1] A. Ohtomo, et al Nature 427, 423 (2004).
[2] N. Reyren et al,  Science, 317, 1196 (2007).
[3] A. Caviglia et at, Nature 456, 624 (2008).
[4] S. Garigliio, et al Review APL Materials, 4, 060701 (2016).
[5] C. Richter, et al Nature 502, 528 (2013).