$\delta$-doped SrTiO3 heterostructure in high magnetic fields

High mobility 0.1\% $\delta$-doped STO magneto-transport has been measured in high magnetic fields as a function of angle. The Nb:SrTiO3 doping layer is 25 nm thick and sandwiched between insulating SrTiO3 buffer and cap layers on an SrTiO3 substrate, putting it well within the 2-dimensional limit. The system exhibits Shubnikov-de Haas oscillations over the entire angle range measured. The resulting interplay between multiple sub-bands as the system approaches the quantum limit will be discussed.