Real Space Mapping of Electronic States in Bi$_{2}$Sr$_{2-y}$La$_{y}$CuO$_{6}$ as a function of Temperature.*

We have studied the single layer Bi$_{2}$Sr$_{2-y}$La$_{y}$CuO$_{6}$ system using high resolution scanning tunneling microscopy and spectroscopy at various temperatures. From these measurements, we have determined the evolution of the local density of states from the superconducting to the non-superconducting state. In this talk, we will describe the evolution of the gap and other spectroscopic features as a function of doping (y=0.2 to 0.9) and temperature (20-100K). Real space maps of the electronic states that show strongly modulated patterns will also be presented. These experimental results are used to determine the connection between the superconducting gaps and the pseudo-gaps in this compound. Finally, we will discuss the similarities and differences between the measurements on the single-layer Bi$_{2}$Sr$_{2-y}$La$_{y}$CuO$_{6}$ and the double-layer Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+x}$.