UC Santa Barbara

We report on the Seebeck coefficient of quantum confined electron gases in GdTiO3/SrTiO3

heterostructures. These structures contain two-dimensional electron gases with very high

sheet-carrier concentrations on the SrTiO3-side of the interface due to intrinsic interface doping.

While the sheet carrier concentrations are independent of the thickness of the SrTiO3layer, the

Seebeck coefficient initially increases with SrTiO3thickness before saturating at a value of

300 lK/V. A model of the Seebeck coefficient, based on thermally populated, self-consistent,

tight binding subbands, captures in a semi-quantitative manner the observed thickness dependence.