Figure 3: Phase diagram showing Fermi- and non-Fermi liquid behaviour as a function of quantum well thickness.

All samples contain a single-quantum well. The thickness is specified in terms of the number of SrO layers contained in the quantum well. The crossover temperatures (filled circles) are determined from Fig. 2 and the fit results. Note that the 1-SrO quantum well shows no crossover within the temperature range analysed, so there is no data symbol for this sample. The diamond symbol indicates the temperature at which the positive magnetoresistance appeared for the 1-SrO layer sample. The approximate location of the QCP, if the transition to positive magnetoresistance is associated with a magnetically ordered phase, is indicated by the red dot. The squares indicate the temperature of the upturn in R_S—no fits were performed below this temperature. All lines are a guide to the eye only and are not meant to indicate crossover temperatures for fractional layer thicknesses. FL, Fermi liquid; NFL, non-Fermi liquid.