Speaker
Description
Two-dimensional electron gases (2DEGs) in SrTiO$_3$ arise in many configurations, of which the LaAlO$_3$/SrTiO$_3$ interface is a prominent example with remarkable properties such as gate-tunable superconductivity. I will present angle resolved photoemission spectroscopy measurements of the 2DEG induced at the (001) surface of SrTiO$_3$, providing insight into the subband structure that underpins all SrTiO$_3$ 2DEGs. I will further show that the strength and nature of electron phonon coupling in the SrTiO$_3$ surface 2DEG evolves as the carrier density is tuned. At low densities, comparable to those found for the LaAlO$_3$/SrTiO$_3$ system, we observe an itinerant liquid of Fröhlich polarons, which places constraints on theoretical descriptions of superconductivity in LaAlO$_3$/SrTiO$_3$.
